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FAQs on the Livebearing Toothed Carps, Poeciliid Fishes Reproduction

Related Articles: Poeciliid Fishes, Livebearing Freshwater Fishes

Related FAQs: Poeciliids 1, Poeciliids 2, Guppies, Platies, Swordtails, MolliesLivebearer Identification, Livebearer Behavior, Livebearer Compatibility, Livebearer Selection, Livebearer Systems, Livebearer Feeding, Livebearer Disease,

Male Xanthistic (note dark eye... not an albino) Sailfin Molly

Re: Question. Exactly how many batch of fry can Terme have from one fertilisation?      9/30/14
<Unknown, quite possibly more than one, with the record for livebearers being six, I believe. So there you go, anywhere between 1 and 6!>
There have been two so far, and I swear I see yet another dark patch in the lower abdomen. Mallow, the male, was in the tank for about 2 weeks before being taken back. *Surely* the sperm haven't been floating around in the tank, sans Mallow, waiting for an opportunistic moment....
<Indeed not.>
Best regards,
<Hmm... do look at, consider buying one of the many excellent livebearer books out there. "Livebearing Fishes (Fishkeeper's Guides)" by Peter Scott is a classic, with lots of species and some very good quality writing and artwork. Currently on Amazon.com for as little as $0.01 plus shipping! Do think you will find this book a very good start to your exploration of the Poeciliidae fishes. Cheers, Neale.>
Re: platy       9/30/14

"Neale's great" I heard myself say out loud..."He's so great" I said again...then I thought, why not tell him!
I will look into Peter Scott's book.
<Cool. It's a good read. There are some other more serious livebearer books out there, but Scott's is by far the best balance between being readable, scientific, and practical.>
<Most welcome. Neale.>

Confusing problem..... Livebearer fry hlth.     Neale's go     6/8/14
Hi I wonder if you can advise me. Let me first start my informing you on my fishes home. It is a 110litre tank 4stage filtration system with pump. Air pump and usually 3-5live plants. Mature tank of mixed platy and guppy. Just out of reach of direct sunlight but still receives natural light and the
built in light goes on for roughly 3-5hrs per night 5-7times a week.
<Seems very odd use of lighting. Why light up the tank at night? Grab a timer, and set the lights to go on for 10-12 hours. Some folks find 6 hours on, 2 hours off, 6 hours on again minimises algae and also keeps the lights on later into the evening, so they can watch their fish. Either way, more strong light will be better for your plants.>
Now for what I need advise on:
My fish had small fry, as I was not expecting them they were in the main tank with all the other fish. I managed to save a lot of them and put them in a breeding tank still in the main water. I have never had cause for concern with any water tests apart from the odd rise in poop which is normal. The small fry are now 5-6months old and was doing really well until recently, one by one never at the same time a small fry starts to go thin from the gills down so it looks like a normal fish head on a thin paper like body. They slower stop swimming and sit on the bottom then die. I cannot understand why??
<From these data, nor can I. Absolutely must have your water chemistry and water quality values to say anything useful. Assuming your water chemistry is hard and alkaline (10-25 degrees dH, pH 7-8.5) then Guppies and Platies should be fine. Adding 2-5 gram marine aquarium salt per litre can be helpful if you have soft water. Water quality should of course be 0 ammonia and 0 nitrite, and low nitrate levels are also a plus, certainly below 40 mg/l. Platies dislike high temperatures, so 22-25 C is ideal for them; Guppies are a bit fiddly in that they originally did well across a wide range, 22-28 C, and "feeders" still are tolerant, but fancy Guppies tend to need more warmth, 24-28 C to stay healthy.>
I feed tropical flake once daily 4 days a week and dried blood worm once on the other three days.
<Try feeding more often; twice a day, and preferably 3-4 times for baby fish under 3 months old. Skip bloodworms as they have little useful nutrition.>
Please help.
Thanks Dave
<Welcome, Neale.>
P.s I do have a video on the last one before it died but the file is too big to add :-(
Confusing problem.... RMF's confused resp.
Hi I wonder if you can advise me. Let me first start my informing you on my
fishes home.
It is a 110litre tank 4stage filtration system with pump. Air pump and
usually 3-5live plants. Mature tank of mixed platy and guppy. Just out of reach of direct sunlight but still receives natural light and the built in
light goes on for roughly 3-5hrs per night 5-7times a week.
Now for what I need advise <advice> on:
My fish had small fry, as I was not expecting them they were in the main
tank with all the other fish. I managed to save a lot <No such word> of them and put them
in a breeding tank
<See/search WWM re these... trouble>
still in the main water. I have never had cause for
concern with any water tests apart from the odd rise in poop which is normal. The small fry are now 5-6months old and was doing really well until recently, one by one never at the same time a small fry starts to go thin from the gills down so it looks like a normal fish head on a thin paper like body. They slower stop swimming and sit on the bottom then die. I cannot understand why?? I feed tropical flake once daily 4 days a week and dried blood worm once on the other three days. Please help.
Thanks Dave
P.s I do have a video on the last one before it died but the file is too
big to add :-(
<Perhaps embed somewhere; send on the link. In the meanwhile, read here:

Scroll down to Platy and Guppy Reproduction FAQs... and read.
Bob Fenner>

Excess Fry, How To Sell - 11/05/2012
Hey all at WetWebMedia,
<Hi, J.! Sabrina here tonight.>
You all have a fantastic website.
<Thank you for the kind words.>
I love searching and spending my off time just reading random bits and using the site to procrastinate from my accounting homework.
<Heh! Glad to know we're.... helping....>
Anyways, I have some Platies and some Guppies. Of course, and I knew this, they make tons of fry.
I do not want to have to 'discard' any of the fry, but I am not sure what to do with them.
<Tons of possibilities....>
I would love to be able to make a little bit of money back on them, though I do know that they are cheaper fish, and don't hold much value.
<Making money off of them will be very impractical. But you might find a local shop that would give you some small amount per fish, or trade you store credit. Local mom'n'pop shops are great for this, and the "really good" ones know the value of locally-bred fish. Although you won't get much at all for these, something is better than nothing, right?>
However, my problem is, I have no clue where to go to sell them.
<Ah. Gotcha. Hopefully you do have some local fish shops? Have you tried speaking with the owner(s)?>
I was looking for some recommendations on any websites or potentially any shops in Western North Carolina that I might could advertise/sell them on or (at the very least) would be an option for me to just give them away to.
<Oh, I see. Perhaps, with luck, someone will read this in the Daily FAQs and maybe you could post something in our forum to see if anyone will respond, knowing of local-to-you shops?>
I have an ad in my local Craigslist, and I have been advertising to any friends that might listen, but it doesn't look hopeful. The fry are still very young and small, so I have time before they are big enough to get rid of but I am quite lost.
<Think about local (or local-ish) pet fish clubs, too. Googling "North Carolina Aquarium Club" yields a few promising leads. I see there's a decently sized group in Raleigh - not western N.C., but maybe close enough for an occasional drive - and maybe there are others closer. A word of caution, though - very often, young livebearers sell VERY inexpensively at fish club auctions (think $1 for a bag of half a dozen or more), and do sometimes get purchased by folks who will intend to use them for feeding larger piscivorous fish. Not all fish clubs are the same, and some are full of guppy geeks who will pay top dollar for prime quality locally bred stuff, too.>
Also, is there anywhere you could point me to crucial information for selling fish online, such as what supplies I would/may need to ship fish, and where I could get those supplies (preferably cheaply).
<For this, you might take a look at Aquabid ( http://www.aquabid.com ) and the like. There are many e-tailers that sell the various necessary heat packs, Styrofoam boxes, etc., and some of those things (like Styrofoam boxes) you may find locally, too. Unfortunately, packing and sending (overnight ONLY, please, and only during appropriate temperatures!) will probably prove cost-prohibitive for these specific fish, unless you have some sort of amazing super-guppy that sells for quite a bit. Selling locally is really the only logical solution otherwise.>
I apologize if I have missed the information on your site, I searched it briefly, but didn't have much time to spend Googling or searching websites.
I appreciate the time and assistance I hope you will be able to provide me, I wish you all the best, and I hope the website continues to prosper and provide a great wealth of useful information to all persons in search of advice.
<One last thing for you to consider, and please don't hate me for it. Have you thought about having a predator-type fish yourself, as a pet? Of course, it would have to live in a separate tank. Some of the most interesting freshwater fish are piscivorous ambush predators....
Monocirrhus polyacanthus comes to mind; this amazing animal eats almost only live small fish and rarely accepts other foods at all. Belonesox belizianus is another obligate piscivore (and a livebearer, to boot!).
These two fish are often considered very difficult to keep and feed UNLESS you have a constant supply of healthy small fish to feed them, and either would make very intriguing pet fish. Polypterids, puffers, Ctenopoma, some Cichlids.... Some catfish, even some shrimp (seriously!) would all gladly consume "extra" livebearing fish as part of their food. So, if you are not opposed to "using" the fry for feeding a predator of some sort, well, that would solve the problem entirely. On the other hand, I can completely understand if you would be opposed to doing this. I'm okay with it, but that doesn't mean you should be. Most people kill spiders they find in their bathroom; I put them outside instead. Everyone's different.>
J Long
<Best of luck finding a solution to your problem. Just remember, it's the BEST possible problem to have! Having your fish reproducing to the point of being burdensome just means that you're doing the best in caring for your pets, and they are happy and healthy enough to do all the things that come naturally to happy, healthy guppies and platies. Congratulations on having this best possible problem! -Sabrina>
Excess Fry - II - 11/08/12

Hello Sabrina, or whomever reads this,
<Me again!>
Thank you very much for the quick and thorough response. I greatly appreciate the assistance. I knew some of that, but I was hoping you would come up with some ideas I hadn't had yet, which you did. Unfortunately, the local "mom 'n pop" lfs near me has told me that they will take the fry from me, but they will not pay me for them. (Which I think is full of crap, because even if the fish die in their tanks before they sold, they are not really out any cash by paying me a slight bit of money/store credit for the fish.)
<Do bear in mind that they do spend time/money on all of the fish in the store....  Even ones given freely to them still have to be fed, housed, cared for....  But to not even offer thirty cents store credit per fish? 
But I haven't spoken with the owner about it yet, but he's very rarely there. Maybe he will have a different policy than the guy that works there all the time.
<I hope so.  Locally bred, healthy animals are less of a gamble than any farm-raised critters, even with the super hardy "bread and butter" fish like platies.>
Anyways, I actually have a few other questions if you, or anyone else that works there
<Hee!  All volunteers, here, no "workers" really.>
could answer them for me.  I have been looking at starting an Orange-eyed Blue Tiger shrimp tank.
<Fun!  Should I mention, I'm a bit of a shrimp geek?>
I have no clue where to start on staging/setting up the tank. First, my water usually tests at a consistent 7.5 ph, and according to the (unreliable) test strips, my water is fairly hard.
<This is good.>
I don't have a test kit to accurately test this yet, but I hope to have one soon. Can OEBTs breed and prosper in a tank with such parameters?
<I think so.>
I don't want to pay so much money for these guys, only to have them die off in a couple weeks or a month and such.
<Then, why not start out trying the less expensive "regular" tiger shrimp? 
Same critter, different color, different price tag.  Much cheaper.  If it works, great.  Sell 'em off and start anew with the prettier, more costly blue tigers.>
The forum answers are so spread out that it is impossible for me to come to a conclusion on that. Also, what type of substrate should I use in the tank? I would kind of like a sand, I think, or something that suits shrimp (that they can move around and such if need be).
<Sand, yes.  Or a very, very fine gravel.  Do not use "pea" gravel or anything else large enough for baby shrimps to get trapped and squished when you go to do stuff in the tank.  Sand is, in my opinion, the best choice.>
I do not know what brand or type of substrate I should get for them, and as far as substrate, what color substrate would make these guys color stand out the most (I haven't seen any in person, so I have no clue what color would make their blue stand out well).
<Uhh, for pure aesthetics, I bet a black sand would look cool.  Or a black plant-tank substrate, like the black Eco-Complete stuff.  Plain old natural sand would look great, too.>
Finally, what type of filter should I use, and how do I set it up?
<I would use a sponge filter exclusively, for a tank intended to breed small shrimp.  I would not employ any other filtration.  All you need is the sponge filter itself, an air pump (not too powerful!) and airline tubing.  Not only will the filter collect debris and keep the water circulating, but it will actually grow all kinds of "stuff" (from the collected debris) that the shrimp and baby shrimp can pick at.>
(also, I have a 5 gallon tank, would that be big enough to sustain and potentially breed OEBTs in?)
I have that 5 gal, with a 5-15 aqua tech filter, but if they breed, I feel like it would suck up the little shrimp, right?
So, is there a product I could use to cover it and not burn the motor in the filter,
<Oh, sure.  Just a plain old artificial sponge.  Use a very sharp knife, cut a slot in it, and slide it over the intake.>
or should I use like a "box?" design filter with a bubbler to filter their water? --on that, how do these work and how do you set it up?
<Works the same way as a sponge filter, basically.  It's just an air-powered device....  but I would use a sponge filter instead for this application.>
Again, I appreciate the answers you have already provided me, and I hope that you can offer me some more great answers to these questions. Thank you so much for your time and assistance again.
<If you can't find the cheaper "normal" tigers to be your guinea-shrimps, you could try cherries instead; they're pretty easy to find, and rather cheap.  Don't forget to supplement Iodine/Iodide.  Search WWM re.  Your hard water should have sufficient calcium, I'd bet.>
<Have fun with your Decapod adventure!  -Sabrina>

Poecilia/Mollienesia gestation period    1/30/12
Hi there Jacquie here.  I have a question concerning how long Mollies are "pregnant" for.  I had a Dalmatian molly that had her babies every 4 weeks.
You could put a clock to her.  I bought a balloon molly and within days of buying her she had babies in my community tank and most got eaten. :(    In my research of balloon mollies I have found a lot of people saying its 60 days before they will have their babies.  Does "pregnancy" lengths differ between the different breeds or are they full of hot air? 
<The gestation period for all Poecilia/Mollienesia spp. is between 4-6 weeks, varying with water temperature (warmer water, shorter gestation).
There's no significant variation between breeds. However, Poecilia/Mollienesia spp. can produce more than one batch of fry per mating, and I'd hypothesize that when people find fry two months after a female was mated, what they're actually seeing is the *second* batch of fry, the first perhaps being stillborn or cannibalised shortly after birth.
Cheers, Neale.>

How do fish determine each other's species and gender? Poeciliids   1/8/12
Obviously, not all fish will mate with each other, but how do fish determine each other's species and gender? 
Watching my male guppies perk up & strut their stuff when a female guppy swims by never ceases to amuse and considering their degree of practically relentless enthusiasm for females of their own species, I couldn't help but wonder why the female swordtails in the same tank fail to elicit a similar response.
<The simple answer is evolution: those males that mated with the wrong species failed to father any offspring, so they died out. It's a bit more complex than this, and often both sexes will do things to ensure they mate with members of the right species, but even so, hybridisation is common among fish. But on the whole, animals will have a variety of ways of ensuring they only mate with members of their own kind, and thereby ensure the energy they put into mating is rewarded with viable, healthy offspring. Cheers, Neale.>

Mollies breeding with Guppy??   8/18/11
Good Day to You All,
<Hello Tracy,>
I just came across your site, and I am pretty new to having an aquarium.
Hopefully it's an easy answer for you.
<We can only hope!>
I have 2 Golden Balloon Mollies (what I think are female) and 1 Fancy Tailed Guppy, male. Any chance they can mate and have fry that live??
Because just this morning, I found a new baby fish living under the log in our aquarium! He is often all over both of the Mollies. Thanks so much for your help!
<Yes, Guppies and Mollies can cross breed. It's fairly common in fact, but the offspring are usually infertile, so nothing much comes of it in the long run. The offspring might be called Gollies or Muppies as you prefer!
Cheers, Neale.>
Re: Mollies breeding with Guppy??
Thanks so much for the quick response! So do you think there was many, but were eaten??
<Hard to say. Guppy/Molly crosses don't seem to happen as often as you'd expect them to, so it might be such crosses produce small broods anyway.
But in a community tank situation many fry will be eaten, so even if the female releases 50 fry, you might only see one or two by the time you get around to looking for them. Adding floating plants helps a lot by providing cover for newborn fry. Once you find them, remove the fry to a floating breeding trap for 2-3 weeks. After that, they'll be big enough to set loose with their parents. If you have predatory fish like Angels or large tetras, then "trap" the fry for longer. Cheers, Neale.>
Re: Mollies breeding with Guppy??
Thanks Neale!!! Your knowledge and help are much appreciated! Cheers!!
<You are most welcome. Cheers, Neale.>
Re: Mollies breeding with Guppy??   8/18/11
Ok, I apologize for this dumb question, and I promise it's the last one.
How do I get this little thing out without hurting it?? It's currently hiding between the rocks and the log we have in the aquarium. Do I just use the net??
<Yes, that can work. But often it's easier to use a net to drive very small fish into a small container like a Dixie Cup or similar, and then decant the fish from there into the breeding trap.>
Thanks in advance, and I won't bother you again about it!! ;-)
<Is not a problem. Good luck, Neale.>

Poecilia/Xiphophorus hybrids, or not, as the case may be...   7/27/11
Hey there!
I sent you a message a while ago about Platy/Mollie breading together and u said it was not possible nothing will come of it.
<Indeed not. So far as I know, these fish are too distantly related to breed successfully, though the male may well try to mate.>
" Ok" I thought, you know more than me about this stuff that will be it then.
<Indeed I do.>
WELL!! She is for sure pregnant and here is the kicker, she was very young when I got her (small) about 6 weeks ago. And in that time she has grown quite a bit. My other male Mollies pay her no mind
<Don't bank on that.>
they don't even stop to look (too busy with the other Sailfin and Dalmatian) I am sure they will soon. The only one who has ever even touched her was my plucky male red platy.
<Quite possibly.>
She is a silver molly who came from a tank of silver mollies. Now I know what your thinking mollies can store sperm for months on end so technically she could be carrying another males young.
But being that she was very young when I got her, won't a male ignore them until they are basically the right age, like mine are doing?
<Nope. The males are sexually competent at about 2 months, when they're about, what, 2 cm long, a bit under an inch in old money. Females need to be slightly older and bigger, maybe 3 months of age, but there's no much in it. Mollies, and indeed livebearers generally, can/will produce young from a very early age.>
I have seen some info on POLLIES but nothing more than individual experiences and some opinion that the resulting fry would either be not viable or born sterile.
<Indeed. When distantly related fish try to breed, the result is either a lack of fertilised eggs completely, and therefore no fry, or else fry that are so weak or deformed they quickly die or simply fail to thrive. Either way, Platy/Molly hybrids are extremely rare, and when they do happen, the fry die within a few days.>
So given this info from me is it possible?
<Possible perhaps, but unlikely.>
She is almost 4 weeks in so I will be putting her in the momma tank soon. I have a method to do it which reduces her stress. No net!
Awaiting your reply Jacquie Brown
<Cheers, Neale.>
Sent from my BlackBerry device on the Rogers Wireless Network
<Why do we get all these messages now where people tell us what Smartphone they use? All very strange.>
Never ending pregnancy?!   7/27/11

Hi there! Ok so I think I have done my homework but this fish is puzzling me! She is in a 5-7 gallon tank with pristine water.
<A Molly, I take it? This tank is too small except for the shortest period of time, days rather than weeks. Mollies get stressed in small tanks, and miscarriages are common when that happens.>
The heat is sitting at 81/82F. She has lights out for at least 16h as they like to give birth in the dark.
<Do they? Never heard of that. They do often give birth among floating plants, so that's what I'd recommend. Floating plants provide cover for the fry and also remove some of the ammonia and nitrate directly, improving water quality.>
She is well fed with a high quality food. I took a section of the mesh bag from a NEW BioMax rocks filter insert and put it over the intake of the filter so the fry can't be sucked up, but will still allow for normal filtration. (Which mind you I take off to clean now and again). There are lots of hiding places for the fry so they can hide
<Fry hide at the TOP of the tank, so rocks, caves, etc. are pointless.
Floating plants, even plain vanilla clumps of "Elodea" type pondweed work best.>
and maybe not get eaten, which she will likely do anyway. She eats very well is very social with me (following me as I walk by and my finger on the tank)
<Begging for food; livebearers generally learn this trick very quickly.>
and seems very happy being the only one in the tank as needs to be. Now the tricky part she has been in this tank for over 4 weeks now and she was pregnant quite a while before I put her in. Her gravid spot has always stayed black and has never disappeared indicating premature birth or abortion and re absorption of the babies. So what could be happening here?
<What's the father? Is this the one you think mated with a Platy? I will make the observation that when Halfbeaks hybridise, sometimes the female fails to deliver the young, and the young die, the female swells up, and eventually she dies. Just one of several reasons why I warn people against hybridisation. In any event, Platy/Molly hybrids are very rare so we might discount this theory. What you can't do is "fix" this in any meaningful way. If she CAN deliver the young, she WILL deliver the young, though some fancy varieties are prone to birthing problems as well as fertility problems. Optimising water chemistry, for example by adding marine salt mix, and either raising or lowering the water temperature for a short period might trigger release. High-fibre foods including cooked spinach and sushi Nori should be used instead of flake, in case constipation is the issue here.>
She must be going on 6 weeks now at least. I thought molly gestation was only 4 are Lyre tails longer?
<4 weeks is normal for Mollies, but it does vary.>
Its hard to find specific breed details in good detail. (Especially with a blackberry).
<Try visiting a library. Lots of books, and the information is often BETTER than what you get online because it's been edited.>
Here is a little video u can see the spot quite clearly when she swims away. Hopefully it works for you. Eagerly waiting your reply, Jacquie Brown
Sent from my BlackBerry device on the Rogers Wireless Network
<Cheers, Neale.>
Re: Poecilia/Xiphophorus hybrids, or not, as the case may be...   7/27/11
Hi Jacquie here again. Thanks for getting back to me so quick.
<No problem.>
The Mollie that has been pregnant forever coupled with another Lyre tail and a Sailfin and when I got her she was with several different breeds of mollies so lord knows what she is carrying.
<Indeed. Mollies will hybridise with each other, as well as other Poecilia species, such as Guppies.>
The little platy had no chance in **** catching her!
<Optimally, you wouldn't keep Platies and Mollies in the same aquarium anyway. Platies prefer slightly cooler water than the farmed fancy Mollies most shops sell, ~22 C vs. ~26 C.>
I was going to set up my 30 Gallon tank so maybe I will just put her in that by herself for now and see what happens. I will keep you all posted about the Platy/Mollie breeding with the silver molly, I am curious about the outcome but being realistic too.
And as well as far as the "Sent from my BlackBerry device on the Rogers Wireless Network" that pops up with the messages. It is something that the phone does automatically with every sent message, it is not something we are doing ourselves. Thanks again Jacquie
<How strange. Free marketing for Research In Motion, I guess. Cheers, Neale.>
"Fish Help" re: unexpected livebearer fry; traps; feeding; Ceratopteris   8/15/11

Hey there Jacquie here again. Just a little update. The molly that was pregnant with the platy aborted the pregnancy (as u said) and the platy has not bugged her since. But oddly no other male has either. Now to the cool news I finally had some success! I put my pregnant Dalmatian Mollie into a newly set up 30 gallon tank (I used water from the other tanks so the cycling would go easier) and sure enough she had her babies after a couple weeks! I was out when she started so she ate a lot of them and a lot of them were still born but when all was said and done I have 7 happy healthy babies! Any suggestions to keep them that way? And also I was thinking of making a Plexiglas (sp?) partition with a lot of small holes in it so I can put a pregnant momma fish in it and keep her away from the babies. Would that be safe for the tank? I figured that would be better than those little birthing nets that they sell at the pet store. Don't know if u can see it but here is one of the little ones swimming around the heavily planted bottom.
<Greetings. There are two ways to handle unexpected fry with the aim of keeping as many alive as possible. The first is to add bunches of floating plants. By preference, fry hide at the top of the tank. Floating plants providing hiding spaces for the crucial first 2-3 weeks needed to get big enough to avoid being eaten. Something like Indian Fern (Ceratopteris thalictroides, sometimes called Water Sprite) is the ideal but at a pinch common "Elodea" (the cheap pondweed sold for use in goldfish aquaria) will work almost as well. The downside to "Elodea" is that is usually doesn't do well in tropical aquaria because it needs intense lighting to survive at high temperatures. Indian Fern is more difficult to get hold of, but it is
infinitely more easy to grow.
The second approach is to corral the fry into a breeding trap, again for the first 2-3 weeks. Breeding traps work extremely well used this way, and in fact I have one in use right now for some newly hatched Oryzias melastigma. Breeding traps have the positive side of being good for allowing you to spot feed the fry without overfeeding the adults, and you can use finely powdered baby fish food in the trap (Hikari First Bites is excellent) 3-4 times per day while offering the adults their usual 1-2 meals of regular-sized flake. The downside to breeding traps is they're unsightly and awkward to install in some tanks. Even if you use a breeding trap, it's wise adding some floating plants too, as these provide cover for the newborn fry and you'll find you're able to rescue far more fry this way compared to just using a trap on its own and hoping some fry survive long enough for you to see them. Floating plants like Ceratopteris also provide shelter for the pregnant females away from annoying or aggressive tankmates. Note: do not put the pregnant female in the breeding trap. Most traps are too small for this to be safe, and the stress can cause real harm
to them, including causing miscarriages. Far better to use the traps for the fry, as/when you find them. Cheers, Neale.>

Platy/Mollie crosses     6/30/11
Hey in my community tank I just got a small (young I think) female silver Mollie. I have noticed my Male Red Platy mating with her and no one else is! (3 other males in tank). Can anything come of this?
<Mmm, in the way of progeny? No... there are other possible cross species crosses... Platies w/ Xiphophorus helleri, others... Mollies w/ Guppies, Endler's...>
I would love to see these hybrid fish! Should I take her out to stop any further breeding with other males. Here is a picture of the male.
<Ahh, very nice. Bob Fenner>

fry question   5/22/11
First I love your website it has helped me out a lot! I have a couple of questions. I have female guppies, and a female Dalmatian molly. One of them had babies. I am not sure if it was the guppy or the Dalmatian molly. The only reason I am thinking that it might have been the Dalmatian molly is because some of the fry are half black around their face, not their fins. I was wondering if this could mean that it was the Dalmatian molly?
<Likely so>
Also my second question is that I have a five gallon tank to put the fry into. As of right now there is no water in it, only some gravel and a bubble wand. Can I just fill it with water from my main tank that the fry
are in right now (they are in a breeding net right now in the main tank) and then transfer the fry right away?
<Yes, this is best; to use the water from the existing larger tank... let the fry tank run for a day or two>
Thank you in advance.
<Welcome. Bob Fenner>

Endless Endler's 5/12/2011
Hello Crew, how are you?
<Fine Carla; thanks>
I believe I have saturated the local Endler's Livebearers market. Although these are wonderful fish, they breed so quickly that they are overwhelming my 40 gallon tank and I can no longer even give them away.
<Ah yes, latter day guppies under propitious conditions>
Could you recommend a really effective predator that enjoys hard water and would eat the Endler's fry, but not the adults?
<To live in the same system? Not really. Best to have another tank for such culling. If you don't have the space, resources for such, maybe a listing on Craig's List or contacting a local fish club might introduce you to someone who does.>
(The males Endler's are quite small.) My water is pH 8.2, kH 9, gH 13, temperature 25C and the tank is well planted.
Thank you and have a great day!
<And you! Bob Fenner>

Fry question   3/27/11
Hi Crew,
I just set up a 10-gallon tank to rear my P. Wingei fry. I moved several in last night, proper acclimation, proper temperature, clean water. I found all the fry on the bottom of the tank this morning. Very strange.
The only thing I can think of is that the HOB filter is creating too much current in the tank and the fish die from fatigue after swimming in the current.
<Can be; air-powered filters are best in breeding tanks. Whatever filter you use, keep current gentle, less than 4 times the volume of the tank in turnover per hour, and ideally 2 times.>
These fry have been pretty hardy in the past. I dropped one into a brackish tank as a feeder without acclamation and it survived easily, so the current is the only explanation I can think of. Is that a reasonable
<Yep, plus the general issue that sodium chloride reduces nitrite and nitrate toxicity, both of which are problems in fry-rearing tanks, as well as the plain fact Guppies generally enjoy very slightly brackish
I'll be changing it out for a sponge filter before I try again, but I wanted to bounce it off you guys, too.
<I use a plain vanilla box/corner filter in my fry tanks, so I can stuff ceramic hoops from mature filters into them as/when required. Sponge filters do need to be kept "live" all the time, otherwise the bacteria will
die (or at least go dormant) between uses. Cheers, Neale.>
More dead fry, Re livebearers   3/28/11

With small corner filter (same air-driven physics as a sponge filter) now installed with low airflow, I moved 5 fry in on Saturday. they survived the night and I moved another 20 fry in yesterday. I woke up today to a bunch of dead fry again. Only 4 or 5 very young fry are still swimming about.
The entire setup is new, not enough time to generate any nitrogen compounds. I dechlorinated. Temperature is the same as the tank I'm pulling them from. I have no absolutely idea what could be killing them. Any thoughts?
<These were the Endler's, right? My guess here would be they were prematurely born. This is not uncommon among livebearers. Such fry rarely last for long. Moving them from one tank to another might have been the final stress that killed them. You'll have a bunch more 4-6 weeks from now -- see what happens that time around. Move the pregnant female into the fry-rearing tank as far before she's likely to release the fry as possible, and carry using a plastic cup rather than a net, so she's not brought out the water. Cheers, Neale.>
Re: More dead fry (ah, for the love of Ceratopteris!)  3/29/11

Catching the females is much easier said than done. They are all wary now and hide at the bottom under the plants. Even when lured with food. (In that way a bit smarter than mollies.) I may need to drain the tank 80% to have a chance at segregating these fish.
<Ah, this is where floating Indian Fern comes into play. This turns your aquarium into a nice safe nursery! The males can't harass the females too much (if all else fails, remove the males to a breeding net or another
tank). Fry can hide among the plants safely for at least a few hours, if not indefinitely, giving you time to find them and remove them (again, to a breeding net or another tank). You'll find many, if not most, livebearer breeders use floating plants extensively. Indian Fern is perhaps the most useful plant in the hobby, and I'd argue only slightly less useful than filtration, and certainly more useful than test kits!
Cheers, Neale.>
Re Fry dying again 4/4/2011

I managed to separate my male, female, and fry Endler's. I put the three largest gravid females into the 10-gallon fry tank with several dozen fry.
Two days later I have lost about half the fry and two of the three adult females.
<I see.>
I bought this little tank used, and I think somebody did a repair job using hardware store silicone instead of aquarium grade silicone. Would that explain my losses?
<Could do. No real way to test it though beyond trying some stock in another, clean tank.>
The fish clamp the caudal fin and seem to shimmy in place while they are still alive. It looks like some kind of poisoning to me, but I guarantee it isn't chlorine or nitrogen compounds doing it. I'm still taking losses after some very large water changes.
<Not good.>
At the same time, I also moved the younger (possibly not gravid yet) females into a third tank and all of them are active and looking healthy. So, fortunately I still have healthy females.
I'm in the process of moving all the occupants from this suspect tank into breeder nets inside the two healthy tanks. I plan to get rid of this tank and replace it.
<Or use as a planted tank, just as is, perhaps with a few shrimps or some such.>
PS: I decided not to go with dither fish with the Pachypanchax playfairii.
They seem to be getting used to the environment now and I don't think the dither fish are needed.
<Agreed, and best kept without if you want them to spawn. Cheers, Neale.>

Ammonia in Fry Tank  1/20/10
Hi. I am new to the whole fish keeping thing.
<Welcome aboard.>
We have a 15 gallon planted tank with 3 female Platies, 1 male guppy, and a snail. About 2 weeks ago I noticed one of the platy's was pregnant (which was a surprise to me since we hadn't planned on breeding them!) I set up a 5 gallon tank immediately so I would have somewhere to put the fry when they were born.
<Actually, it's often easier to leave the parents and the fry together. If you add lots of floating plants, a surprising number of fry will survive.>
I treated the water with Cycle, and added some decorations from my other tank in hopes of jump starting the bio filter.
<Ornaments and water conditioners will have little/no useful effect. To really jump start a new tank, try removing media from an established aquarium. A filter can stand to lose up to 50% of its biological media without any problems. That means it's easy to divide up the media in your established filter, put up to half that media in the filter for the new aquarium, and end up with two "cloned" filters, both fully matured!>
After several days, I added the pregnant female. The next day she had her babies. I let her stay overnight, hoping some of the fry would hide and survive. In the morning, I moved her back to the 15 gallon tank (she seems to be doing fine.) The fry are now 5 days old (I think there are 6...they are tricky to count), and I am having trouble keeping the ammonia at 0. It always seems to waver between .5 and .25 ppm.
<Ah, this will kill the fry quickly.>
I have been doing daily water changes of about 50%, adding an additive to remove the chlorine and chloramine. I'm assuming a big part of the high ammonia is due to the frequent feedings.
<Can certainly be the case. Indeed, the trickiest part of rearing newborn fish ensuring good water quality. Urgency means we tend to use new aquaria, often with new filters. Factor in the amount of food they need, and you have a double whammy situation that means the baby fish often get exposed to worse conditions than the adults.>
Should I be concerned about ammonia at these levels?
What else can I do to help reduce it?
<Three-fold. First, clone the mature filter to quickly get biological filtration working in the new tank. Secondly, remove uneaten food promptly (a turkey baster is ideal for this, just slurp out whatever hits the bottom of the tank). Finally, do more water changes. You could also add a little salt, maybe 2-3 grammes per litre. Salt has a mild detoxification effect with regard to nitrite, and since Platies and Guppies are highly salt tolerant, this is a cheap and cheerful tonic. Doesn't work with most fish, but with livebearers, it's worth a shot. Alternatively, you could stock the adult aquarium with floating Indian Fern, add the babies, and hope for the best. Incidentally, if the baby fish aquarium gets good light, adding some floating plants will help too. They absorb ammonia directly, and also carry lots of bacteria on their roots, so act like little biological filters.>
I would appreciate any advice. Now that we have these baby fish, I would really like to see them survive!
<Good luck, Neale.> 

The mystery of disappearing fry   1/18/10
Hi guys and gals,
You did a great job helping me deal with finicky guppies that used to drop dead on me for no apparent reason. Now I'm back with another puzzle. Here is the setup: a 38G community tank that's been running for a while, complete with all necessary gadgets. The gang consists of 5 guppies, 7 mollies, 5 platys, 3 pre-adolescent clown loaches, one red-tail baby shark Seeking, and a 5 black ghost knife don't ask why, the oddball was inherited.
<This fish will of course eat baby fish, given the chance.>
I used to have a smaller tank (had to get rid of it after continuous complaints from my co-habitants) with a mesh breeder in it and this is where all of the fry from the community tank parents was hanging out.
<Do bear in mind breeding traps are somewhat less useful than you might imagine. It's often best to keep livebearers in single species tanks filled with floating plants; usually, a surprisingly good portion of the fry survive under such conditions. Traps and nets can work, but fry will jump out, and some fish will chew through the net at night (catfish and loaches especially) producing small holes through which fry can escape.>
Since the smaller tank became no more, the breeder was moved into my 38G and attached to the wall. One fine morning I woke up to find that all of the fry except two were missing. After a few vocal displays of frustration and disbelief I went on to examine the breeder which turned out to be structurally intact.
<Do remove the net, if it is a net-type trap, and review CAREFULLY.>
I pondered what could have happened for a while before falling asleep and woke up this morning to discover that one of the two survivors a lovely Dalmatian Lyretail molly fry was gone. Now all I have in there is a 4 week old guppy.
<I see.>
Needless to say, I'm bothered by what have happened. The fry could not have escaped on its own.
<But they can jump.>
Its also unlikely that they were caught through the mesh walls of the breeder as those are rather stiff and the mesh is fine.
<Check for holes.>
The only possible answer is that some deviant fish jumped from the main tank into the breeder, helped itself to baby fish AND jumped back out into the main tank.
<Possible, though I admit unlikely.>
This is rather advanced thinking for aquarium fish, isn't it? And who is to blame? I'm leaving the ghost out the thing cant decide on whether it can swim, let alone jump who else? Clown loaches?
<Can chew nets.>
They always hang out in the corner together scheming something and looking suspiciously super cute Anyone has experienced this before?
<Yes; lost various fry when an Ancistrus catfish decided to graze algae from the net. I now don't bother with traps much, and instead use 8 gallon tanks with heaters and simple filters to rear fry, or else leave them with parents and tonnes of Indian Fern.>
<Better luck with the next batch! Neale.>

Re: The mystery of disappearing fry  1/21/10
Oh fry can jump?
<Not very far, I admit...>
I had no idea! I guess I keep drawing parallels with those clumsy little human babies...how wrong of me.
<Ah, yes, very wrong. Livebearer fry are ready for the hurly burly of life in their stream or pond right from the start! Sure, they're small, but they're MUCH bigger than baby fish from eggs, and in terms of senses and muscles, they're essentially identical to the adults, just scaled down.>
Anyhow. Yes there was a hole in the net after all.
<See! I'm good at this...>
I fixed it. I'll keep the breeder covered from now on. The good news is that I am (as of yesterday) a proud mommy of a new batch of fry. Guppies this time.
Also I was thinking of making my own livebearer food - perhaps a modified version of the European shrimp mix.
I'm thinking veggies, Spirulina, shrimp, some antiparasitic component for prophylaxis folded into a gelatin base. Any advice or suggestions on this?
<Wouldn't add/use medications unless there's good reason. Just as with human babies, acquiring a healthy gut flora and building up natural immunity are all crucial to their development. But almost any mix of cooked peas, algae (Spirulina and Sushi Nori) plus some other vegetables would be great. Shrimp is fine to a degree, but contains thiaminase, and this can lead to vitamin B1 deficiency, so use in moderation. There's a nice recipe here:
A big clump of Indian Fern is also good. Partly, the fish eat the roots and leaves, but also the feathery roots trap algae and infusoria, and these are very good for small livebearers. I can't imagine breeding fish without this wonderful stuff!>
Many thanks,
<Cheers, Neale.>
Re: The mystery of disappearing fry  1/21/10
Was this ever fun!!
I think I should patent my 'fish food mud' and sell it to local spas as a super-gross-looking-eternal-youth-treatment. I even added some rhubarb. And cloves. Do you think fish might enjoy rhubarb?
<Not sure... the leaves contain oxalic acid, and raw at least rhubarb stems are incredibly bitter. I happen to like raw rhubarb, but was warned that it can lead to things like gout. So be careful. Personally, I'd avoid.>
Now...I know I'm being carried away by some nerdy bubbly current but I have a bag of edamame in my freezer and it made me ponder phytoestrogens and their effects on fertility in mammals. But fish...I know nothing about fish. Is their a consensus among fish knowledgeable folks on whether feeding soybeans to fish can modulate their reproduction?
<No idea. But beans and peas can be used to feed fish, in moderation at least. In fact the things to avoid are mostly things that have strong peppery or mustardy flavours. These could be toxic. Most everything else is safe, and will simply be ignored if the fish don't like it. Surprisingly perhaps, Piranhas can be quite partial to bird seed. So there's plenty of scope for experimentation.>
Oh WWW, the constant source of inspiration...
<Glad you're enjoying the hobby. Cheers, Neale.>

Breeding livebearers
What is the difference between Mollies and Platys?
<Well, there are at least five species of Molly (Poecilia spp.) in the trade, and at least two species of Platy (Xiphophorus spp.) so this is a bit difficult to answer comprehensively. But generally, Mollies are bigger, more streamlined in shape, prefer warmer water (26-30 C), and generally need to be kept in slightly brackish water (preferable marine salt mix, at least 3-6 grammes/litre). Mollies need very hard, basic water (pH 7.5-8, 15+ degrees dH). Mollies are adapted to feeding on algae, and have distinctive jaws used for rasping algae from solid surfaces. They also have adaptations that allow to live in swampy conditions by breathing the very top layer of water, the bit with the most oxygen, which looks somewhat like air breathing in Gouramis (though it isn't). Male Mollies use their dorsal fins for display, and some species have greatly enlarged ("Sailfin") dorsals. Platies are usually smaller, have a dumpy or rhomboid body shape, and need cooler water (22-25 C). They do not need to have salt added to the water, though like Mollies, hard, basic water is essential (pH 7.5, 10+ degrees dH).>
My local fish store has them mixed in one tank and they titled it as mixed one week after I bought what I thought were mollies!
<How odd.>
can you tell me what I can look for and what the difference is between recognizing the stages of pregnancy?
<You really can't tell the stages of pregnancy. Contrary to popular belief, the "gravid spot" only applies to small livebearers, such as Guppies and Mosquitofish, and even then, is easily misunderstood, especially where colourful forms of the fish are being kept. So, assume any female kept with a male (of its own species, or at least genus) is pregnant. Keep the female in a quiet tank away from the males, and install lots of floating plants, such as Indian Ferns. DO NOT use a breeding trap or net, as these stress livebearers, especially the bigger species, resulting in miscarriages. An 8-10 gallon tank is ample for 1-3 female Mollies or Platies. After about 4 weeks, the fry will emerge, and you'll find them at the surface hiding among the floating plants. Now you can net them out, put them in a breeding trap or net, and rear them in there until they're big enough to keep with the adults (takes about 3-4 weeks). Ideally, keep the female in the breeding tank, apart from the male for a week or two so she can fatten up.
Males are notorious at harassing the females, and you'll get bigger, healthier broods if your females are in good condition each time they mate with the males.>
I originally bought 1 male and 4 females to try my hand at molly breeding <Good luck. Much written at WWM about this topic. Cheers, Neale.>

Neglected 55gal aquarium
We had someone looking after our 55 gal aquarium for the winter. It contained 8 Glo-light tetras, 4 Corys, 6 female guppies, 3 pairs of swordtails. The aquarium was probably too well stocked with cover for the fry (plastic plants). Needless to say, the aquarium was extremely neglected and when we returned not only was there an inch of waste on the gravel, there were two Glo-lights, 2 Corys, 3 adult pairs of swordtails (one male not original) and a multitude of fry of various ages (I'm sure well over 150). In addition, the ten male guppies (which we had in a separate 20gal) had been added as their tank started "leaking" (the filter had clogged!) - so there are numerous guppy fry in the mix now too.
Surprisingly, none of the fish looked sick, all were active though we did find a couple of swordtails fry dead on the bottom under the muck!
<After a crisis, you do see fish populations dying back to the level the tank now supports, with the more delicate species dying first, as with the tetras and catfish.>
We immediately started vacuuming the tank, doing water changes etc., etc. Ammonia levels and nitrate levels quickly (I was surprised how quickly) read zero - even though we continue to vacuum lots out of the gravel. But we still have this overpopulation problem.
<I see...>
We have gotten the 20 gal back in almost working order. We checked the tank for leaks, found none; rinsed some of the gravel (it stunk), added some gravel from the 55gal, added some water from the 55gal, filled up[ with fresh water. Initial ammonia and nitrate levels were 2.0 mg/L and 50mg/L respectively. The last reading today was ammonia 0mg/L, nitrate 0mg/L. We will try to find a nitrite kit tomorrow to make sure every thing is in order before adding fish.
What is the best thing to do with all these fish? The local pet store doesn't want the fry and the owner is not very knowledgeable. Is there a predator who might help control the livebearer population?
<Most anything carnivorous will do the trick: Angelfish, African Butterflyfish, Aplocheilus spp. killifish, Glassfish all spring to mind.
Does depend on how hungry such fish are; Angels eat fry when they can, but they're pretty inept predators and would just as soon take easier foods like flake. African Butterflies and Asian Killifish on the other hand view fry as prime foods, and will eat them in preference to flake.>
We have read that angelfish like guppy fry, so we were thinking of one angelfish and the guppies in the 20 gal. - then we'd keep the males and females together. In the 55, keep the swordtails, Corys (maybe get a few more) and... more Glo-lights to make a school? a predator who likes swordtail fry but not adults? Keep the all livebearers in one tank and buy a fish who likes live food in the 20gal and feed him/her the fry?
<Sure, if water chemistry is acceptable; a school of Glassfish for example will chow down on any livebearers they can find, and being tolerant of brackish water, are ideal for use in systems where salt is used.>
Remove a lot of the plants so the fry cannot hide as well (or is that a no-brainer?).
<That would certainly make a difference.>
Any suggestions would be appreciated.
<Cheers, Neale.>

Re: Neglected 55gal aquarium  05/23/09
Thanks for getting back to me. I don't think our local pet store stocks much exotic stuff, but the Asian Killifish sure do look like "some fish"!
<Most any pet store should be able to get "Golden Wonder" killifish, a variety of Aplocheilus lineatus noted for very bright colours; besides being long-lived and adaptable, this species is super-predatory! Cheers, Neale.>

Re: 'Linia' (Livebearers; Limia nigrofasciata), sys./repro.
Dear Neale
<Hello Emma,>
Sorry to bug you again, can I pick your brains on your breeding setup for the Limas as you are having such success with them.
<By all means, but there's no great secret! My tank for the adults is a Brillux 60 Complete Aquarium, with 72 litres of water (about 19 US gallons). It's thickly planted with Hygrophila, Vallisneria, Anubias,
Cryptocoryne and various floating plants. The top is really thick with plant leaves and the roots of floating plants. Otherwise, there's nothing very special about the system. It's 50/50 rainwater and tap water, for a
hardness around 10 degrees dH and a pH of about 7.5. Normal filtration and temperature. The tankmates are peaceful catfish and gobies, though I have added a Glassfish now to try and eat some of the baby fish (yes, I know, mean).>
I've got them setup in a book/Google recommended tank just wondered if you had any personal tips that I might have missed. I have to admit I've added two more females but its a reasonable sized tank and looked a little lonely with just the pair in there .
<Ah, I did start with one male, three females. And I didn't get any fry at all when they lived with halfbeaks, who I suspect will eat the fry given the chance.>
Hope all's well with you
<It is indeed.>
<Good luck, Neale.>

Re: 'Linia' (Livebearers; Limia nigrofasciata) 4/26/09
Dear Neale
May thanks once again, just to let you know the good news I discovered five baby Limia in the tank last night one only mm's from a very uninterested females nose so rather chuffed this morning!!
Two more females look ready to pop so awaiting the arrivals eagerly.
<Sounds like you'll soon have lots of lovely baby Limia to look after.
They're quite easy to rear, though as always with livebearers, remember to give them lots of small meals across the day, and if you have to ignore them for a few days, leave a sliver of cucumber or something for them to nibble on.>
Hope your weekends fab
<Has been so far...>
Best regards
<Good luck, Neale.>

Aquarium (plant and fish repro; how to reduce the numbers of fry, plants) 04/22/09
Hello again, Neale,
You helped me so much before, and I hope you can help me again.
<Will try.>
I have a 240-liter aquarium, and everything is going well. Too well, for that matter. When I first got the aquarium and didn't know what I was doing, I had a problem with fish and plants dying. Now that I know a little more about how to take care of them, the fish are reproducing like rabbits and the plants are taking over the aquarium.
<A-ha! Yes, this is what should be happening. In the case of the plants, all the plants you cut out and dispose of are removing nitrate and phosphate from the water. You are literally watching the plants help clean your tank! As for the fish, like most animals, if they're happy and healthy, they'll breed!>
I have friends who said that they would be glad to take the excess fish and plants. However, how can I control the excess growth (both fish and plants)?
<There's no advantage to slowing plant growth; simply cut back the excess, aggressively if needs be, and dump the waste on the compost heap. Fast growing plants tends to mean no algae problems; rein back the plants any, and the algae often picks up the slack. As for fish, judicious use of predators can make the difference. Angelfish for example are remarkably good at eating livebearer fry, as are African Butterflyfish and Asian Killifish (Aplocheilus spp.). Turning down the temperature to the lower end of the preferred range for a species will tend to cool their ardour, and stretch out the gestation period of livebearers.>
What am I doing wrong?
Any advice you can give me will be very much appreciated.
<Cheers, Neale.>

Can a Mickey mouse platy mate with a guppy?  3/10/09
<They can "mate" in the same way donkeys and horses can, but the female will not become pregnant.>
I have one Mickey mouse platy in my tank and three female guppies and I did have two male guppies that have died. I have a rather large fry that survived and is thriving but the bigger they get they look more like the Mickey mouse platy than there guppy parents (orange female and a blue tuxedo guppy). There are nine total and they have the black tail which I initially thought was blue but now the also have black dorsal and anal fins?
I am confused can you help???
<Definitely NOT platy/guppy hybrids. As the fish mature, you'll see which ones are Poecilia and which Xiphophorus, and all will be revealed! Cheers, Neale.>

Dead fry, what's the cause?   2/21/09 Hi again, For some unapparent reason i lost my baby platy i had 3 platys not 3 guppies. I went out at 11:30 this morning when i got back at 5:30pm i went up to give them their second feed and found it dead and decaying, in that day something had killed it, but it was with my baby guppy in the breeding box they were the only 2 in there they got on well they had the whole breeding box to them selves they were still tiny so i didn't want to risk letting them into the big tank yet as i know adult fish eat any babies in the tank. What could have happened? I was treating my tank with Myxazin and yeah it said when using a lot to remove fry, but i wasn't using a lot i don't have to use it at all now cause my male mollies eye is better please answer my question. Thanks, Alishia. <Almost always, baby fish die because of either [a] starvation; or [b] poor water quality. Don't rely too heavily breeding traps or nets; while they sound good in theory, you can really only put a few fry in them before they become overloaded. Water circulation through such traps/nets can be poor, and if the water overheats or goes stale, the baby fish will die. Why were you using Myxazin? It's an anti-Finrot medication, and if you have Finrot, you have water quality issues. So grab a nitrite and a pH test kit, find out what's the matter with your tank, and work from there. Once you have those numbers, get back in touch and we'll help some more. Do remember Mollies and Guppies have very specific requirements, and indeed Mollies are much better kept in brackish rather than freshwater conditions. Guppies and Platies won't mind a little salt, so by all means grab a box of marine salt mix (e.g., Instant Ocean) and add to each new bucket of water at a dose of 3 grammes per litre. Marine salt mix (as opposed to "aquarium salt") will buffer the pH and raise the hardness as well as salinity, and your livebearers will be MUCH healthier. Good luck, Neale.>

Ok now I'm getting annoyed. Re: Dead fry, what's the cause?      2/21/09 Hi again, I am seriously getting annoyed because my aqua center has told me right and wrong of what to do with my aquaria and Myxazin treats: Fin and body rot, Ulcers, cloudy/pop eye and other bacterial infections <Yep. Myxazin will treat those diseases, though not always successfully. It's a typical antibacterial; reliable when the disease is caught early on, but less reliable if the diseases is advanced, in which case an antibiotic will work better.> and i looked at the bottle to say all this to you, my water quality is fine so that tells you. <Tells me what? Define "fine". For baby livebearers, it's 0 ammonia, 0 nitrite, less than 50 mg/l nitrate, pH 7.5, and moderate to high levels of hardness. In the case of Mollies, the addition of marine salt mix to the water at 6 g/l makes a huge improvement.> NO thanks for the wrong advice again, Alishia <No thanks to who? If you're dissatisfied with what I'm telling you, then please, carry on talking with your retailer and buying whatever the heck he (or she) recommends. I couldn't care less. All I am telling you that when fry die, it's usually either starvation or poor water quality, so those are the issues I'd be worrying about before all others. If your fish are sick, then there's a reason. It's up to you to find out what. Randomly adding medications hoping for the best isn't going to work. Cheers, Neale.>

What's your opinion on where to put pregnant live bearers?  2/5/09 Hi there! What a fantastic site! I've spent the last 8 hours, (literally!) reading, with fascination, about the many live bearers out there! <We're glad to be here to help.> First up, I'm in the UK, so I work in litres, and daren't get the UK/US gallons conversion wrong, so I'll just talk litres with you! <Prefer metric, so fire away.> I have a 60l tank that houses 32 fish, (including a whole load of tetras so please don't tell me off about size/gallons etc.!), <Hmm... just because you ask us not to point out a problem, doesn't make the problem go away!> plus the following live bearers - Guppies 2F (pregnant!) 3M, Platies, 2F, 2M (I've had one 'pair' for about 6 months, with nothing, but the other pair are a recent purchase, so here's hoping...), Balloon Mollies - 2F (never had anything from them in 6 months), Dalmatian Mollies - 1F (who I suspect is pregnant, though her partner passed on a day or two ago), Swordtails - 1 pair and their daughter (and I think Mum is pregnant again!)! <Ok, that is a lot of fish for 60 litres. There's really no getting around that. So you do need to be careful with water quality and water chemistry stability. I don't tend to recommend mixing livebearers with tetras because (at least some) livebearers do best with a bit of marine salt mix added to the water. Just a bit, 3-5 grammes per litre, but while that helps the livebearers, tetras won't appreciate it at all. It's worth mentioning at this point that marine salt mix isn't the same thing as "tonic salt" or "aquarium salt", neither of which help that much.> I used to have 14 fish in a 25l tank, where there were at least 2 lots of births from the swordtails, of which we only ever saw the one baby, who's coming on very well now, and is almost 2 months old! I bought the larger tank a month or so back, because I can't bear the idea of live food, and babies being eaten, so I have reset up the 25l tank with gravel, couple of snails, some plants etc., thinking that when my lovely girls get fatly pregnant, it would be a good place to put them. <Would recommend putting a single female at a time in here, and only for the minimum time. Move her using a jar, not a net, so you don't squeeze her belly (that would cause a miscarriage). The ideal thing is actually to leave females where they are, but install lots of floating plants. The fry congregate there, and if you're reasonably attentive, and the tank isn't filled with predatory fish, you can scoop the fry out and move them to the breeding tank. I find that fry often appear overnight, so check the floating plants first thing in the morning as well as during the day.> Is this really the best thing to do? <Best? Perhaps not. But viable. Do make sure the filter in the 25-litre tank is fully matured, e.g., by putting some media from the 60-litre tank into it. Keep it clean, and do lots of water changes. Feed 4-6 times per day, but in small amounts. Segregate fry as they mature, because bigger ones *will* steal food from the smaller ones.> Having read over the past 4 years worth of questions on your site, there seem to be those in favour of letting nature take its course (my plants aren't really big enough yet, not many hiding places), putting in a breeding trap/net, or removing the mother into another tank, letting her have her fry and then putting her back in the original tank. <Breeding nets/traps shouldn't be used for anything bigger than a female guppy, period.> The reason I ask is because I wasn't expecting to have 4 pregnant females at the same time, and that might be too many, plus babies, in a 25l tank - carnage.... <Save the fry you can. Don't lose sleep over the ones you can't save. Each livebearer has the potential to produce literally hundreds and hundreds of fry per year, and with just a 25-litre tank at your disposal, there is NO WAY you can rear them all.> For reference - in the tank, in addition to the above, are a dozen or so tetras, a couple of catfish, 2 zebra Danios (a male and female, given their sizes) and a couple of small barbs. <Well, most tetras and barbs will eat fry given the chance, and the Danios certainly will> I do hope you can help me with some suggestions/thoughts to where I should place the delivery suite...! Regards, and thanks in advance! Samantha <Hope this helps, Neale.>

Re: What's your opinion on where to put pregnant live bearers? Thanks so much for taking the time to reply to me! <Pleasure.> Just quickly, the only reason I mentioned the number of fish/litre ratio was that I've had fish stores jump to the conclusion that I've crammed my tank full of the 'larger' variety of fish, when in reality (after lots of research) my fish are, in the majority, of the small tetra size! They are all very happy, very lively, swim in mini shoals, and don't, in anyway, appear to be distressed. I would be humane and pass them back to the stores if I felt that was the case. <Cool.> Anyway, I want to thank you for your advice, I'm watching the fish very carefully, day and night, and have the smaller tank cycling nicely, with water from the large tank, in readiness. I think I'm going to wait and watch. If any of my mothers show signs of impending delivery, I'll move them if I can, but otherwise, I'll just have to hope that I can catch any fry that survive. <Good luck!> My intention with the fry isn't to keep them all, I plan to donate them to hospitals, surgeries, schools etc. in the area (typically, my sons' school doesn't have a tank anymore!), and onto any friends who want to replenish their own stock. <Sounds like a worthy plan.> My Dalmatian Molly isn't showing a gravid spot, but she is a pure white molly with black spots, and is squaring round her belly, so I'm working on the theory (and hope!) that she did get pregnant before her partner passed away. <Oh dear.> I do have one further question that I can't seem to find an answer to. <Fire away!> My tank is fully lit, but when I go to bed, I turn off the light. First thing in the morning, I turn the lights on again, and give the fish about 10 minutes to 'wake up' and come out of their hiding places before I feed them. I've noticed on a few occasions over the last week that when I first turn the lights on, that on the 2 female guppies, their gravid spot is a distinct pink colour, rather than the black that seems to evolve in the space of about 10 minutes. After that, the black is on full display, all day, till, I presume, after I've turned the lights off. <Ah, many fish change colour at night. It's quite normal. Fish "think" their colours. Humans are born the colours they are, though luckily for the make-up and hair dye industry that doesn't stop us wanting to change things. But fish are different: they have colour-bearing cells in the skin that require nervous impulses to display particular colours. While not usually chameleon-like in most cases (though some fish are) most fish will change colours depending on age, sexual/social status, background colours in their environment, and yes, time of the day.> I've also noticed that my neon and Glowlight tetras don't seem to be quite as 'neon' when I first turn the light on, so I'm wondering if this is a pigmentation issue, or something completely different! <Again, precisely the same thing.> Could you shed any light on this for me at all? <It's nothing to worry about, and just a neat piece of natural history for you to observe.> Many thanks again, for your help. Samantha <Happy to help. Forgive my brevity; technically I'm "out" doing other work Monday/Tuesday but wanted to reply to your message. Cheers, Neale.>

Re: What's your opinion on where to put pregnant live bearers?  2/12/09 Neale, again, another great thank you for your very informative replies! <Happy to help.> We've got babies! I spotted 1 late last night, nestling at the top of the tank, so whipped it out (in a glass) into the spare tank. This morning, my husband spotted another, so we had that one out too, then about 3 hours later, another 3 surfaced, so they were rescued, and finally, at lunchtime, a 6th got spotted! <Cool!> Absolutely no idea who the mother is, because they all still appear to be pregnant, including the about-to-pop guppies.... Oh well, will wait and see as they develop! <Indeed!> Regards, and thanks again! Sam <Good luck rearing your babies. Always great fun! Cheers, Neale.>

Re: What's your opinion on where to put pregnant live bearers? 02/28/09 Afternoon All! A quick update and a question! Those 6 fish became 12, who are now 17 days old! Have determined that 6 are guppies, still quite grey and transparent, but have elongated and are developing black markings on their tails. The other 6, no idea! Pure white, shorter and squatter than the guppies, so they could have come from anyone! On a technicality, my balloon mollies are both females, one silver, one peach, but have been in my tank for exactly 6 months, only a day or two ago, so could be them.... same colour, but no pot belly...! Anyway, as of today, I spotted my other guppy girl nestling around some of my floating plants, not interested in food etc., so I used a pint glass and gently transferred her to the 'nursery', where she has produced 22 babies (so far) that are swimming nicely, shoaling etc. My question is, she seemed to want to try and escape when I first put her in the tank, swimming up and down and up and down the sides etc., but seemed happy enough to drop the babies, started doing it again, had more babies, and has started doing it again now. In fact, unless she's giving birth between, when I'm not looking, and she's eating them (it's been 5 hours since she first went in), she's doing it permanently. Should I remove her back to the main tank now/imminently/later tonight??? Thanks once again in advance, I was very pleased to catch 2 drops on video, and have managed to take some brilliant pictures of the babies, very very clear. Happy to pass them on if you think they might be useful to other WWM readers! Sam <Hello Sam. Molly babies tend to be rather rotund compared with Guppies, so it's entirely possible you have a mixture of both. As for when to move females from breeding traps, the best answer is "ASAP"! If at all possible, try and move any males away from her, ideally to another tank. This will allow the female some time to feed and relax before being turned into a baby factory again. By all means send along some photos of your baby fish, and we'll post them on the daily FAQ page. Cheers, Neale.>

Re: What's your opinion on where to put pregnant live bearers? Hi Neale! I moved her in the afternoon, when the count of fry had sat at 25 for about 3 hours. She wasn't in a trap though, she (and they!) were in a 25l tank, with the other fish, and yup, looking at them more closely, I think the other fry are mollies....! Anyway, we have a count of 25 guppy babies, plus the others, she'd already started having babies in the main tank, we rescued 1, no idea how many others there were! Attached 3 pics, including some of the 'older' babies with their blackening off tails too! The one with the shoal of new fry are when they were literally only an hour or two old, some only about 20 minutes! Very newborns Sam <The babies loo happy and healthy. Welcome to the most rewarding part of the fishkeeping hobby: fish breeding. This is, in my opinion, an objective test of your skills since you have so many things to get right. Sure, livebearers are at the easier end of the range, but still, there is plenty to keep you busy as you maintain good water quality, offer them the right foods, and generally ensure they grow at an optimal rate. Do try and offer them some algae: it's really useful for livebearers, giving them something to nibble on during the gaps between regular meals. Cheers, Neale.>

Marigold swordtail and guppy fry  10/7/08
I have a 30 gallon tank which is currently holding about 15 mixed guppy's and marigold swordtail fry, then a 46 gallon tank in the basement with about 75 marigold swordtail fry. They are about 6 to 7 months old. Some of the guppies look pregnant already, and the original tank which held the parents seem to have yet another swordtail and guppy that are pregnant. I have them both in a breeding cup. I have been extremely successful with swordtail births in the breeding container before as well as the guppies. I originally started with about 6 fish. I need to know if it's possible for the fry to be pregnant already...how can I tell the swordtails apart male from female, and should the siblings be separated? I have well over 100 fry living from the original 6 fish...HELP
<Donna, the short answer is you can't magically make the males stay away from the females. As soon as they are sexually mature they will attempt to mate with any females they have access to. The normal way to breed livebearers is this: you remove the fertilised female to another tank where she can release her fry safely. After she gives birth you put her back in the community tank. In the meantime you watch the fry develop. After two months, and before three months, the males will be sexually mature, so that is your deadline for observing them and then removing them to a tank of just males. Eventually you will end up with all the males in one tank, and all the (virgin) females in the other. If you don't have two tanks for the juvenile fish, then use a tank divider to split the tank into two halves, one for the males, and one for the females. Within 3-4 months, the fish should be big enough to sell or give to other hobbyists. Simple as that. Cheers, Neale.>

Re: marigold swordtail and guppy fry 10/07/08
I understand most of what you said but I am having trouble in the 46 gallon, telling the males apart from the females.
<Pretty easy... look at the anal fin; on male livebearers, the anal fin is tubular and bent over into a rod-like structure. Since the males start of with triangular anal fins like the females when young, you can tell they're sexually mature once their anal fins change shape.>
The original tank upstairs, has two males that have a long black straight sword tail.
<Irrelevant to sex determination. While it's nice that male swordtails have big tail fins, you absolutely cannot rely on this to sex them, because this structure won't be obvious (if present at all) on young males.>
They have created all this!!!? I can't see this black sword on any of the males in the basement. Not one of them show the black mark.
<Forget about it. Concentration on the anal fin.>
Could I have 70+ females?? They are over 6 months old, should I be able to tell the males from females at this point???
<Yes; the males will have obviously modified anal fins.>
The guppies are separated in the dining room and some of the fry are already pregnant but at least I can tell which ones are the males.
<Cheers, Neale.>

Re: Molly, Platy crosses... 8/30/08  9/17/08
Hi Neale,
Thanks for your reply to my original question about mollies and platies cross breeding! I have finally motivated myself to get a few images of the fry I ask about, though the lighting in here is terrible and good images are very hard to get!
I have attached a couple of images of the two lyretailed mollies I have (both male and the only mollies in the tank) and the only 2 clear(ish) shots of the fry that I managed to get. Also, here is a link to a YouTube clip of some of them
<All look very healthy (and your cat sounded mighty interested, or hungry).>
The fry are growing well and the mothers are almost ready to drop the next batch. Even though the fry have platy mothers with vivid red, white, blue/green, black and white colourings, the fry have the yellow and black colouring of the mollies.
So now how does it look? Do I have freak cross bred fishies or am I as horribly confused about it as I feel?
<These look like regular Mollies. The complicated thing is this: both Mollies and Platies can store batches of embryos, so you can move a female to another tank without males, and then she produces fry some months later, the result of a mating that might have happened anything up to six months later. It's also difficult to sex some of the fancy livebearers because modifications to the anal and pelvic fins obscure the basic anatomy. The fish in the photo labeled "matydaddy2" for example might look like a male, but it's almost certainly a female. The anal fin is large and triangular, though the two extended pelvic fins could be mistake for the gonopodium. Consequently my assumption is that the juvenile fish are her offspring. Mollies are sexed by looking at the anal fin: on females it has the normal shape, on males it is crooked, and bent over into a tubular structure that looks a bit like a stick.>
Thanks heaps,
<Hope this helps, Neale.>

Living with expecting tank mates and other questions : Marbled Mollies, Hi-Fin Tetras, Platys and a Loach    9/6/08 Hello, I am new to the site, and I have read many of the posts which have really helped me get to know my new fish! I do however have a few questions in relation to my personal situation. I have a 29 gal tank that housed multiple Goldfish from March to July 08'. I kept my albino weather loach,(Golden Dojo) in the tank as she is quite calm and gets along with anything. I have even kept her with snails,(which they eat in the wild) and she never even nudged them! <All sounds nice.> She also keeps my tank clean and I prefer her to an algae eater,(catfish.) <Agreed; a better combination for the coldwater tank.> I have a three-piece "Sunken Pirate Ship" which is rather large and provides excellent hiding spots for the fish! In fact, the Dojo sleeps in the middle portion of the ship every night. I also have one live plant which I am not sure of its name. I purchased it as a dry bulb and it has grown in the tank which is next to a window,(at least half of the tank gets sunlight everyday.) I also have a rather large, fake, "plant" which I keep at the top of the tank, half in the water. I have a water heater which is recommended for a 30-60gal tank, and it seems to keep the water around 74-78 degrees. <Slightly on the warm side for both these species; scale back to 20 C/68 F and you'll be in the "sweet spot" for Weather Loaches and Goldfish. At warmer temperatures, you're more likely to cause/experience problems than otherwise.> I also have one long bubble wand in the back of the tank, and bubble "toys" at each front corner of the tank. The Dojo likes to lay on the long wand and swim through the bubbles! I also have a large double filter designed for a 30-60 gal tank, and a small single filter for a 5-15 gal tank that I use to help get the tank clear after I clean the rocks and cycle the water. <All sounds great; where Goldfish are concerned, "super-sizing" your filtration system is always a good move, and I'd argue essential for long-term success.> Anyway, now to my question. After I took the Goldfish out of the tank, I let just the Dojo live in the tank for about two weeks while I treated the water and cleaned the tank, cycling the water every few days. We had an issue with a parasite in the water before and I wanted to make sure everything was clean,(the Goldfish had a thick slime-coating all over, and slight fin-rot.) I thoroughly cleaned my "Pirate Ship" and all of the toys, rocks, plants and the tank itself before introducing new fish. <Do understand that excess slime production and Finrot are both symptoms of water quality or water chemistry issues. They don't "come out of the blue" for no reason. So, check the nitrite level, to ensure the water is clean, and check the pH, to make sure it is stable around 7.5.> My Dojo never had any signs of illness, but I also treated the water with Melafix, Ick Cure and Salt even after I moved the Goldfish, just to be sure. <Well, Melafix is largely useless, and Ick Cure is redundant and arguably dangerous when used randomly. Ick medications contain copper, and copper is toxic to fish. We use them on the basis that the copper dosage will kill the parasites before it kills the fish, but be under no illusions that the copper is bad for the fish even so. Hence you should never use medications unless you have an express reason to do so. Do always remove carbon when using medications, otherwise they don't work reliably, if at all.> Around two weeks ago, after all signs of the "slime" were gone or cleaned, I decided to add a few fish in with the Dojo. I purchased 3 Black Mollies,(2 marbled females and one black male.) 2 Platys,(1 male and 1 female.) and 2 Hi-Fin Tetras,(not sure of the sexes.) I have been adding API Stress Coat to ease them into their new environment, and I add API Aquarium Salt to ensure healthy fish and water. <Not a good combination for several reasons. Did you read up on the requirements of these fish? Mollies must have very warm water, 26-28C/78-82F, preferably with salt added at a dose of 3-6 grammes per litre. Such conditions will be too warm for the Weather Loach. The usual Hi-Fin Tetra is a species called Gymnocorymbus ternetzi, a notorious fin-nipper. Mixing with Platies and Mollies, which move quite slowly, is asking for trouble.> I read that all the fish in my aquarium like a little salt in their water, but not a full marine environment. <Tetras can't bear salt; they come from soft water habitats, so adding salt to the water is stressing them. Mollies demand *marine salt mix* not that "aquarium salt" guff retailers will try and push on you. This "aquarium salt" is just table salt and doesn't raise the pH or hardness, so won't help the Mollies much. Platies don't mind a little salt, and will be fine at 3-6 g/litre. Loaches don't want salt, so again, they're being stressed in the long term. Please realise adding salt in "teaspoon per gallon" doses has no basis in science. It's something inexperienced aquarists get told about, and because its cheap, they do it. But you will do a lot better skipping tonic salt and concentrating on what water chemistry your fish actually need.> Everything was going fine. I had wondered if the Dojo would get along with the new fish, and she hasn't even looked in their direction so far. The new fish don't seem to be scared or intimidated by her at all, so I think all is well with their new tank-mate! <Ok> Here is where I need advice. Around the 1st of Sept. I noticed that the new females,(there are three, 2 marbled Mollies and an Orange and black Platy.) All look swollen and pregnant! I had anticipated this, but didn't realize it would happen so quickly! One of the Mollies likes to lay her bulging belly on top of the heater! <Dangerous: she can easily become burned doing this.> The other Molly likes to hide with the male in the big mass of plants on the top of the tank while the Platy just hides in one of the Pirate ship sections and sticks with the male when she's out eating and mingling. To my surprise, all the females actually seem to take a dominant role ! <The female certainly isn't "hiding with the male"! Be sure to think like a fish, not like a human. Mollies don't have pair bonds. The male is staying with the female because he wants to mate with her. He'll as soon eat her babies as anything else, so there's nothing nice going on here.> Anyway, I wanted to know what you would do in this situation. Should I separate the females from the males now? <If you want to rear the babies, then yes, moving the females into another tank is a good idea. Scoop them with a jar, not a net, so you don't press their bodies and damage the babies inside them.> Do the females also need to be separated from each other? <No.> I have another 29 gal.. tank, but it isn't set up and I don't even have a filter for it yet! How long will it be before the fish give birth? <Gestation period is around 1 month.> If I purchased a small 10gal tank and set it up, would it be aged enough for the fry when they arrive? <Yes.> What about breeder nets? <Waste of money.> Can all of the fry be kept together once they are born? <Yes.> What do I need to feed the fry? <Algae and finely powdered flake food.> Also, and most importantly, what can I do to make sure that the Moms are comfortable, and live through the birthing process! <She'll be fine. Again, think outside the human experience. Fish don't have a pelvis like a human, so there's no bones in the way of the birth canal. The babies slip right out, no stress or discomfort. Mollies do miscarry when stressed, but that's something else. Usually caused by males pestering them or by aquarists putting them in nets or breeding traps.> Do fish usually live or die during/after birth? <Your Mollies will fine, and looked after properly will have many broods across their ~5 year life span.> I have a 6yr old Son whom enjoys helping me take care of the fish, and he'll be crushed if something happens to the Moms! He is thrilled at the prospect of new baby fish right now, but I need to prepare him for the death of the Moms if it is a common occurrence! <It's not. Mollies normally die because people put them in freshwater tanks with freshwater fish. They get Finrot and Fungus. But breeding isn't an issue.> At the moment, I do not have any ph, nitrate, or ammonia levels for you as I have never used the kits before. I hope you can give me some good ideas as I plan on giving the fry every chance for survival! <Please do read our articles on Mollies and Livebearing fish generally: http://www.wetwebmedia.com/FWSubWebIndex/poeciliids.htm http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Mollies can be kept in freshwater rather than brackish water, but it's an uphill struggle because the pH must be high (7.5-8.2), the hardness as high as practical, and the water quality 100% perfect all the time. I'd honestly recommend setting up a brackish water tank just for your Mollies. Fill with suitable floating plants and you should be able to rescue at least some every month. Put the babies in a breeding net for 6 weeks, at which point they'll be big enough to be turned loose in the main tank.> I thank you in advance because I think what you are doing for these people/fish is a great thing. I remember how helpless I felt when I started my first tank, and here I am again with my first "live bearers." Often you feel as if you have nowhere to turn, and its hard to find people to help you when you really need it! I had an issue with a Black Moore earlier in the year, and my plea for help went unanswered on another site! The Black Moore died, and I found out later that she just needed a few green peas to ease her digestion! <Quite so.> Fish, like so many creatures, cannot speak for themselves. It is up to caring, responsible individuals to look after their needs and treat them humanly! Personally, I think the traditional "round Gold-Fish bowl" should be outlawed! I personally stopped a group of teenagers from buying one of these "death traps" just last week! <Well done!> I commend you for your selfless quest to help the fish of the world! Anecia <Very kind of you to say so. Cheers, Neale.>

Re: Living with expecting tank mates and other questions : Marbled Mollies, Hi-Fin Tetras, Platys and a Loach 09/07/08 Hello Neale, and thank you for such a timely response! It is nice to know that someone is there to help you when you feel helpless. As for my own experiences, I have learned that it is better to avoid obvious mishaps when it comes to fish, and I am going to take your advice and correct my mistakes! <We are happy to help.> First of all, I cannot believe the pet store sold me these fish knowing they needed different water needs,(fresh vs. marine!) <Actually a common mistake. Mollies can be kept in freshwater tanks (they certainly don't need a marine tank). It's just they're not very hardy, and 50% of the time (no kidding) they get sick. In brackish water, by contrast, they're practically bullet proof. And in marine tanks, the same. It's a contentious and complicated issue why this is, and whether or not they can be kept 100% healthily in freshwater tanks. Some argue not (like me) others argue it is possible, provided you obey the key rules (possibly true, but impractical for casual aquarists).> From what I can see, my Loach and Hi-Fin Tetras need to be in a freshwater tank, and the temp needs to be considerably cooler than the Mollie/Platy tank, right? <Platies are fine in coolish water, around 22-24 C (that's 72-75 F) will suit them well, and will work nicely with Weather Loaches. The Gymnocorymbus will be fine in that too. It's a common mistake to keep South American tetras too warm; Neons for example like quite cool conditions, and "burn out" if kept warmer than 25 C/77 F. It's really just the Mollies that don't like cool conditions. They're very much "hothouse flowers" and thrive at balmy temperatures many other fish don't care for so much.> I went out and bought a 10 gal tank last night, and, as I mentioned, I already have a single, 5-15gal filter, which I have already been using for at least a few months. If I use this filter in the new 10gal tank, will that prevent "new-tank" syndrome? How long should I wait before moving the fish into the new tank? <Moving a mature filter from one tank to another, if done quickly (i.e., within 10-20 minutes of switching the power on/off) works extremely well. However, the water chemistry between the tanks should be the same; at an extreme, taking a filter from a saltwater tank and connecting it to a freshwater aquarium won't work. Try also to minimise temperature differences; doesn't need to be exactly the same, but keep the difference to within a couple of degrees. You can also move filter media, taking up to 50% from a mature filter and putting it into the new filter.> The new tank can go marine or freshwater right now. <The marine tank? Do you mean a saltwater tank with corals and whatnot, or a tank that's had a little salt added but contains freshwater fish?> I will definitely separate the loach and tetras from the Mollies and Platys, but which should I move to the new tank? <Mollies certainly need a 29 gallon tank minimum, and I'd not keep them in anything less than a 20 gallon tank in the short term. They are sensitive to water quality issues for a start, but they're also big, active, and by community fish standards, quite aggressive (the males anyway).> My 29gal tank was the one that I put the "Aquarium Salt" in, but you said that it probably isn't helping anyway, so I could easily revert back to freshwater. <Absolutely.> On the other hand, should I move the Loach and Tetras into the small tank, and let the 29gal tank be the marine tank with the Mollies and their new fry? Your call. <I'm not wild about putting either Loaches or Tetras in tanks smaller than 20 gallons to be honest, so it's six of one, half a dozen of the other. For now, I'd look at the size of the fish you have, and act accordingly, bearing in mind some of these fish will grow and may need different quarters in the long run.> I bought a small heater for the 5-10 gal tank. Will this be adequate? <Can't possibly tell from here! Depends on the temperature of your home for a start. Try it out and see. If the heater is constantly on but the tank stays cool, it's likely underpowered for the job.> I was thinking it would be for the Loach/Tetras since they do not need a very warm environment. From what I can tell, the Tetras and Loach will be stressed will the salt, and I am afraid they might take it out on the slow-moving Mollies, so I need to separate them soon! <You may be fine with your Gymnocorymbus; some people report no problems with them in community tanks. I'm just telling you what sometimes happens, so that you're prepared.> Also, I need to purchase the right kind of salt for the Mollies. What should I ask my retailer for, and is it sold in some of the larger retail stores,(IE: Wal-Mart, etc..) If the general aquarium salt I bought isn't doing any good, then the Mollies need help right away! <What you're after (ideally) is the salt used in marine tanks. Many brands: Instant Ocean, Reef Crystals, etc. They're all fine for this. Buy whichever is cheapest. All you need do is add 3-6 grammes per litre of water (0.5-0.8 oz. per US gal) in each new bucket of water. Stir well, and when the salt has dissolved, pour it in. All livebearers will tolerate this level of salt, so you can keep Guppies, Swordtails, Platies and Mollies all happily in this as you wish. They will be hardier and healthier.> Also, thank you for clearing up any misconceptions I might have had about Melafix, and Ick Cure. I won't use them again without consulting a professional! <It's not so much we're professionals, as we're not trying to sell you anything -- and that's the difference. Some stuff is essential in life, but other things... not so much. In the long run, it pays to know what you need and when to use it.> Again, some of these pet stores just don't care what they sell! <The operative word is "some". There are many excellent pet stores, often the "mom and pop" places where the managers are hobbyists themselves. But even so, it's like buying a car or a computer -- the salesman will have an angle he's trying to push, and you need to have done your research so you know which questions to ask and which sales ploys to avoid. Spending $10 on a basic aquarium book is money VERY WELL SPENT. Bob and I have put together a list of our favourites, here: http://www.wetwebmedia.com/FWSubWebIndex/bookswwmsugg.htm Have a nose around, and see if your local library or bookstore has these volumes. If you click the Amazon links, check to see if you can buy the book Used; that'll save you more than a few pennies.> Anyway, one of the two sets should be moved right away to accommodate their needs,( either the 3Mollies/2Platys or the 2Tetras/1Loach. ) Please advise me as to what you would do in this situation! <I'd keep the Platies and Mollies together as a Livebearer system; you can become a "specialist" with that tank and learn about them and breed them as you wish. Put the other fish in the (slightly cool) tropical tank at 22-24C, and if you add other fish, be sure that you check they'll be happy under such conditions. Many fish -- such as Danios and Corydoras -- absolutely LOVE slightly cool conditions. But there are a few, like Gouramis and Angels, that aren't so keen.> I have noticed that the male Platy doesn't seem to like the Mollies very much. Do these species live together well? <Males of most livebearer species are mutually aggressive. Keep the tank spacious and stock with floating plants and/or tall plastic plants and they'll coexist up to a point. But this is why I repeatedly make the point here and in magazines -- livebearers aren't "just add water" easy fish! They are demanding in their way, and also very rewarding once you get everything right.> I have another 29gal tank, and I am planning on setting it up soon. I might move the Platys into it, and let the Mollies and their new fry have a tank all to themselves! <Sounds great. But I'd honestly put it to use as your main community tank, and leave the 10 gallon tank for rearing baby fish and putting pregnant females in so they can rest-up away from the males. Giving female fish restful quarters so they can give birth and/or recuperate after laying eggs is a VERY GOOD THING and will get you serious time off Purgatory!> Also, you are right about the male Mollie pestering the females. There is one female that he stays with all the time, and she gets aggravated and makes him go away! Will he always pester her, or will things get better when the fry mature? I suppose its better to have a lot of females and only 1 or two males! Correct? <Correct; 2 females to 1 male is the baseline, but the more females the better. You'll soon have her daughters so I wouldn't go buy a bunch of fish now, but one extra female might make all the difference. When you're rearing your fry, sell on all the males and most of the females, but keep a few of the girls for your "swarm" of Mollies so the mothers and daughters can all hang out together.> I hope everything works out for our new fish, and I am going to do everything I can to make sure they are healthy and happy! Again, thank you for taking the time to help me, I would never have known that I wasn't giving the new fish all they needed to thrive! Sincerely, Anecia <Glad you're enjoying your hobby and learning all there is to know! Cheers, Neale.>

Baby Fish, Livebearer Repro. I have had 2 sets of platys, 2 guppies and 3 green swordtails. I have been waiting forever for them to give birth. I know they get a black spot and look like they are going to explode right before. My question is how fast do they give birth? Do they all come out at once, or 1 every hr., etc. The reason I ask is that I found 1 baby orange platy today. The mother still has black inside, however it doesn't seem to be by her anal fin. Also, I have put a few females in the breeding tank before, however they abort. Is there any other 'Sign" to look for? I'm afraid to do it too soon. I believe I read that platys, guppies etc. could be every 3-4 weeks. Thanks Kim <Hi Kim. The "black spot" you mention is known as the Gravid Spot. It is only reliably visible on Guppies and other small members of Poeciliidae; larger species, like Platies and Swordtails, don't always show the spot. That's because the spot is a colour patch but rather the developing embryos pushing the uterus against the muscle wall of the abdomen. The bigger the fish, the thicker the muscles, and the less visible the uterus becomes. So forget about the gravid spot. Instead, concentrate on the shape of the female. Prior to birth, she will be extremely rotund. In any case, as you've learned, putting the female in a breeding trap doesn't work with anything except the smallest species (e.g., Guppies). By far the best (and I'd argue ONLY) way to get fry from mothers kept in community tanks is to add floating plants. Indian Fern is ideal: http://www.wetwebmedia.com/PlantedTksSubWebIndex/ceratopteris.htm Simply check the tank every morning, and look for the babies among the leaves! Simple as that. Cheers, Neale.>

Re: Baby Fish  7/3/08 Thanks! I will definitely try the floating plants. 3 females that I have are definitely round and look like they are ready to burst! That is why I was wondering if the orange platy is possibly still giving birth since I found 1 baby 2 days ago. How long does it usually take for all babies to be born? 1-2 days, hours, weeks??? Thanks again! Kim <If you find one or two babies, and then nothing for days, then the chances are all the others were eaten! Typically livebearers release their batches of fry within a short period. In my experience, you look in the tank one morning, and find all the babies swimming about among the plants! Cheers, Neale.>

Platies, Guppies; repro  3/3/08 I have two male guppies and one female platy along with some other bottom feeders, i just started a ten gallon tank so i only bought a few to let the tank cycle. I am pretty sure that the platy is pregnant from the store and the guppies like to chase it around the tank and bite at it's fins. I has taken to hiding in the bottom corner but comes up to eat. What should i do to relieve stress of the platy during the pregnancy. I have an extra tank but no filter to add to it. I had planned on maybe putting her in it for the babies to grow. If you could please reply back at XXXX@yahoo.com that would be much appreciated. thanks, Cody <Hello Cody. Two things: first make sure the aquarium is big enough for these fish. A 10-gallon tank is too small; 20-gallons is the minimum. When kept in small tanks livebearers can be nippy towards one another, as you're learning. As for stress, the main thing is to remove the males. They will fight constantly, and nothing you can do will stop that. They will also eat any babies. Whatever you do, don't put her in a "breeding trap" -- these are too small for adult fish; at best you can put the babies in them. Adding some floating plants will also help the female fish and give protection to the babies for long enough for you to find, rescue them. Do read here: http://www.wetwebmedia.com/FWSubWebIndex/poeciliids.htm Specifically the sections of guppies, platies and breeding. Cheers, Neale.>

Guppy and Molly Babies   2/8/08 Hi- I recently bought fish (4 guppies and 2 mollies) and someone had babies. I have been looking online for answers and I thought maybe you could help. I can't tell if the mollies had babies or the guppies!! ~Fish Lover~ <You really can't tell when they're very small, though baby Mollies tend to be a bit bigger and more dumpy-looking than newborn Guppies. Do remember that the fry are at great risk of being eaten, so you'll want to add some floating plants to give them shelter and a bit of safety. Breeding traps work up to a point, but baby fish often don't do well in them, so I prefer to move newborn fish to a small aquarium where they can be reared properly. Cheers, Neale.>

Re: Guppy and Molly Babies 2-9-08 Thank you. I do have floating plants in my aquarium. I am keeping them with my other fish, though. None of them seem to be eaten or bothered, and it is fine by me if there is only one still alive because I don't know if my ten gallon tank can hold much more. Thanks. ~fishlover~ <Happy to help. A 10-gallon tank is far too small for Mollies, and realistically too small for Guppies, or at least, any group of Guppies that includes a male. Male Guppies will harass each other and unreceptive females in small tanks. As for the Mollies, unless you adding salt (at about 6 g per litre) you will have real problems keeping them healthy because they are so very sensitive to Nitrate. Do remember "loving your fish" is less about cute names and more about providing them with optimal living conditions. Animals don't give a rip whether they're loved, but they do notice if they aren't cared for properly. So do plan ahead, monitor water chemistry and water quality carefully, and be prepared to make changes when (not if!) they are required. Here at WWM we don't hand out advice just to be awkward, but to help. Cheers, Neale.>

Re: Guppy and Molly Babies I went to PetCo to get the fish. The fish person said that that was a good amount of fish. They are all very healthy. ~fishlover~ <Who ya going to believe... someone who wants to sell as many fish as possible, or someone who has been keeping fish for over 20 years and makes his living writing for fish magazines and books? Seriously, a 10-gallon tank isn't big enough for Mollies, and will be a war zone if you have more than one male Guppy in there. Sure, they're fine now. But that might not last. Mollies usually need salted water to do well, which Guppies don't mind, so add the marine salt mix and be done with it. A mere 6 g/litre isn't going to cost you much. Feel free to read any aquarium book about Mollies and Guppies, and you'll find much the same advice I'm giving you here. I'm labouring the point only because you sign yourself "fishlover" which kind of suggests that you actually care about the well-being of your fish. If not, and you're happy to take the risk of them fighting, damaging each other, getting stunted, poisoned by nitrate, or whatever because they're just cheap little pets you bought on a whim, that's your own choice. But perhaps a change of nickname might be in order? Cheers, Neale.>

Re: Guppy and Molly Babies Ok, well I will do my best but....never mind. I don't have any male guppies. <Good stuff. Do remember that some of your baby fish are likely to be males, so even if you just bought females from the pet store, three months from now you'll have sexually mature males throwing their weight around. So plan ahead. Cheers, Neale.>

Re: Guppy and Molly Babies 2-9-08 Thank you. I saw a black spot on some of the babies on their tails. Does that mean that they are female? <In a word, no. I suspect you are thinking of the famous (infamous) "gravid spot", a dark region that appears around the back half of the ventral surface of the abdomen of *some* female livebearers when they are close to delivering their brood. It is a hopelessly unreliable sexual characteristic even for telling if female fish are pregnant, so in cases of limited RAM for storing useful fishkeeping facts, drag that particular file to your brain's Trash icon and delete. Guppies (and most other livebearers) are best sexed by looking at the anal fin; after a couple of months it should be apparent that some of them have normal fins (females) while others have modified, rod-shaped fins (males). Cheers, Neale.>

Platy and swordtail fry  2/7/07 Hi <Hello> I have two questions. One, is that I have 1 red platy fry and 3 swordtail fry. All the rest of the fry squeezed themselves between the glass and rocks and killed themselves. What were those fry thinking?! <Mmm... trying to avoid predation?> Second, I've had 2 red platies give birth in my comm. tank and I haven't seen one single fry. Do you think that they all just got eaten after the first day? thanks. Sean <Could be... do take a read on WWM re Poeciliid reproduction... Bob Fenner>

Livebearer birthing clinic.... 1/15/08 Hello there, <Hello.> I have sought you out previously for advice and your team has been spot on. About 8 months ago I purchased a few mollies (6) for my 60L tank and 7 Guppies for my 30L tank, I managed to stabilise the water conditions and both fish groups were kicking around very healthily - too healthily in fact. <Oh?> My Mollies have now multiplied from 6 Adults to 3 Adults, 30 juvenile and 30 baby (with more baby on the way), and the Guppies have gone from 7 Adults to 6 Adults, 10 Juvenile and about 40 baby. <Well done.> I have visited all the local pet shops and aquarist stores supporting Tropical Fishkeeping, and all of them refuse to take Mollies due to their incessant breeding and lack of 'factory controlled' conditions of life. I advertised for a few weeks in the local paper to no avail, and I asked around all the people I know - I managed to get one friend who was on the verge of purchasing an aquarium (110L) when he read up on Mollies and decided to buy some fish of his own (non-Mollie) instead of having free ones off me. <Shame. Mollies are lovely fish!> I started off as a pretty inexperienced Tropical Aquarist, but now I am confident in my abilities and have been looking to other fish (for instance Bichirs etc.) however I only have space for the 2 tanks, and I am left with over 100 fish eventually. <Yikes!> It's getting close to critical point - 2 water changes a day in each tank, very soon the nitro cycle will disappear and the bacteria will perish - forcing the ammonia levels to skyrocket. <Indeed.> Any enough monologue, I have a few questions, if you don't mind... <Go ahead...> What options are left for my Guppies and Mollies? <Try visiting online Fish Forums. There are many. Some have Buy/Sell sections, where you can easily offload unwanted fish. If you have wildly multiplying livebearers, one solution is to install a smallish predator. Seahorses, for example, happily eat baby Mollies kept in marine aquaria, but even in a fresh/brackish system, things like Glassfish and Halfbeaks and Sleeper Gobies will chow down on fry.> Say, I eventually managed to sort out the Guppy and Molly issue, would a Bichir in the 60L be excessive by itself namely this one ( http://www.tropicalfish4u.co.uk/Fish/Freshwater/MiscFish/CuvierBichir ) ? <60 litres is a bit small for Polypterus senegalus. That fish can comfortably get to 25 cm in captivity, and while it isn't overly active, you still need to respect the fact it's a fairly big fish. A 120 litre tank would be the minimum, in my opinion.> Also, I am considering upgrading my 2 aquariums to a single Marine Environment and have a few questions - is it just the inclusion of the Protein skimmer and high salt that is the difference between the 2 types of aquariums? <Depends on where you're going with the marine tank. I've kept coldwater marines in tanks that were basically nothing more than coldwater freshwater tanks but with salt added to the water. This sort of approach is viable with hardy marines that live in coastal habitats and don't really care much about water chemistry fluctuation. But once you start with reef organisms, things get A LOT more complicated, a LOT more quickly. Skimmers, UV, quarantine tanks, sumps, high-output lights, Redox, all become part of the picture. These are things that, for the most part, are optional or not necessary in freshwater tanks.> - Does/Can Live Rock substitute Protein Skimmers? <Nope. Do read some of the many EXCELLENT articles about the topic here at WWM by the various marine gurus.> - Is it possible to get a silent Marine setup (bedroom you see...) <Quite possibly, but not if it has a skimmer, sump, etc. But I kept my coldwater marine tank in my bedroom when I was teenager and it was fine.> - Do Marine smell at all/more than Tropical? <Smell different, I suppose. Salt water does have a distinctive "tang". Some say it's iodine, others ozone. Whatever it is, it is a nice smell.> Thanks for your assistance, GZ <Cheers, Neale.>

Re: Livebearer birthing clinic....  1/16/08 Thanks for the quick reply. <No problem.> I will look into some of those species that you mentioned as small carnivores - I don't think seahorses are available here in the UK, <Yes they are, but they're expensive because they're tank-bred nowadays. This makes them infinitely easier to keep than wild seahorses (they eat dead food!).> nevertheless, a conversion to fish-marine is possible since this tank has Mollies in (I also have some small Suckermouth Catfish - are they capable of reverse osmosis too ?). <No, Plecs cannot live in seawater. Do check you understand what "reverse osmosis" means -- nothing to do with seawater!> I have just a few more questions: - A friend in Germany has several huge tanks, 90L, 200L, 300L and always advises against the 'all-in-one' commercial filters/pumps. He instead used (from what I can remember) a foam layer which is permanently fixed to the aquarium walls in which the pump is placed behind. Overtime it matures as the bacteria reside in it, and starts to look like a rock face of sorts. Is there a correct name for this filter medium - I cannot find any reference to this at all, and have since lost contact with my friend. Would such a filter be overkill in a 60L tank? <No filter is "overkill" if it provides at least the amount of filtration required for the livestock being kept. A too-big filter can be a waste of money in terms of purchasing and running costs though, and too much water current upsets fish from relatively still waters. All this said, I can't really see what anyone would object to a commercial filter. It is true that manufacturers are sometimes optimistic about how much livestock or what size tank a filter is suitable for. But provided you go by turnover, no harm will be done. A basic community tank needs at least 4 times the volume of the tank in turnover per hour, a big/messy fish system at least 6 times, and marines and giant freshwater fish at least 10 times.> With tanks, is it always wise to go for surface area over depth (for chemical loss via aeration)? <In theory, yes, a filter that it wide but shallow, with all the bacteria close to the atmosphere will indeed outperform one that is tall but narrow, where the bacteria must rely on the oxygen supplied by the flow of water. In practise this isn't usually an issue, and other things, like water changes and water circulation, will have a much bigger impact on the livestock than the shape or design of the filter. PROVIDED of course that the filter is adequate in terms of turnover and the choice of filter media.> The Mollies and Guppies I currently have in the juvenile state, about 14 of them, smaller than adults but a lot bigger than fry, what could I do with these? Nobody in the local area on forums wants Mollies, and some folk explicitly advise/abhore female mollies and Guppies for the 'population explosion' risk. <Can't think why. Anyone sticking either in a community tank with, say, cichlids or small predators such as swordtails or Pim pictus catfish isn't really going to have a population explosion!> Thanks for your help, GZ <Cheers, Neale.>

Platys.... what if? Molly crosses?    1/3/08 Hi Guys or Gals! <Hello.> OK, so.. about 9 months ago my cousin dumped some mollies and platys in my freshwater tank due to them being baby making machines at her house. I got sick of my freshwater tank constantly having problems with disease and infection so I pulled the Mollies and over the course of many, many long hours, I slowly converted them to marine fish (in their own separate tank not in with my other marine fish) They're doing great! (both tanks) Its been 6 months. Some are Dalmatian mollies and some are molly and platy cross breeds (living in a 1.024-1.025 salinity). <Never heard of Platy/Molly hybrids. Are you sure? I'd LOVE to see pictures of these Platy hybrids.> I even have a couple new babies in that tank. So my question is.. are the Platys solely freshwater? <While Mollies adapt to marine conditions fine, I've never heard of anyone adapt any Platy (or Swordtail) to marine conditions. Brackish water up to SG 1.005 is likely the limit.> Or can they be converted like the mollies as well? <Not that I'm aware of.> I heard they'd be OK in brackish water, But I want to know if they'd live comfortably in a marine environment. <Likely not.> Thanks for your time. Rochelle <Cheers, Neale.>

Pregnancy Question - 11/26/07 Hey it's me again! If the gravid spot is not the pregnancy clincher, then what is? I've noticed that at the end of the belly and right next to the anal fin forms a point right before she gives birth. -Any help? -Sarah <The problem with the gravid spot is that it isn't a surface feature. It's caused by the embryo-filled sac being pressed against the muscle wall of the abdomen. So you see a dark area just in front of the anal fin. It's very reliable on wild-type Guppies and Mosquitofish. But as soon as you look at fancy livebearers, which have stronger colouration, or larger species like Platies or Swordtails, you can't see the gravid spot because the colouration and/or muscles obscure it. As a general rule, if a female livebearer above around 2-3 months has ever been with a male more than 2 months old, she will have been fertilised. Since livebearers can have as many as six broods from one insemination, you effectively need something like 6 months or so of time to completely "use up" any sperm deposited and so be "ready" for mating once more. This is why people breeding livebearers separate males and females as soon as they can be sexed, and never, ever mix males with females except for deliberate breeding purposes. Once you've had a few broods, you will probably be able to tell for your particular fish what they look like a few days from parturition, but beyond that, you cannot reliably tell whether a female is actually pregnant or not. Hope this helps, Neale.>

Platies and Swordtails changing sex  10/26/07 I love your website. I'm very sorry if this topic is already on your website, I've already looked as much as I possible could. I'm doing a mid-term project in science class. I am going to see if Platies can change gender. I have to look up info to support it. I know that only hermaphrodites can change gender. I also know that it can only happen to females, and that it takes longer for guppies to change sex than platies or swordtails. I'm actually going to do the experiment, how long does it take, approximately, for them to change? Also that there must be all females present, no males. I already own a lot of livebearers, adults and babies, I've had fish my whole life. Can you help me please? Thanks a lot. <Greetings. Without wanting to do your homework for you, let me save you some effort on one aspect of your project: There is no evidence at all any Xiphophorus species change sex. As your literature review should reveal, while it has been mentioned in the aquarium literature many times, it has never been observed under laboratory conditions. It is widely believed to be a myth, with aquarists having misidentified a slow-developing male as a female. Sex changes in fish tend to confined to marine perciform groups. The classic examples are among the Wrasses, which typically start off as females, but the largest ones become males. This is called Protogyny ("female first"). Protoandry, where all individuals start off as females, is not so common, but one well-known example is the Anemonefish, where the largest member of a colony becomes the female. Cheers, Neale>

Setting up fry/quarantine tank, livebearers, platies 09/29/07 I'm new to this hobby and I really appreciate having this site to go to for help.? I have a 10 gallon tank set up in my classroom with 3 female red? wag platys.? I've had the platys for almost 3 weeks now and they seem to be doing pretty well.? One likes to hide at times, but she'll always come out for a pinch of food and sometimes she hangs out with the other two so I think she is Ok.? Anyway, our school's back-to-school night was last night and one of my? students'? parents (who used to run a fish store in NY) said one of my platys was pregnant.? <Pretty much a steady state...> I had? thought she? might be because she? has a fatter belly than the other two, but I didn't know if maybe she was bloated/sick.? I? do not see a dark spot on her so I'm assuming it will be awhile longer for her to give birth.? I know it is a long shot to think that I might be at school when she has her fry and can actually save them from being eaten, but I thought I'd set up a tank to use as a fry tank just in case.? <Can use a trap of a few designs... or add some/more hiding material... trust to chance... some young should survive in such a setting> And besides, if it doesn't get used as a fry tank, I could use it as a quarantine tank for any new fish that I want to add to my tank.? I'm going out this weekend to get the supplies to set up this tank.? My question is how to best get this fry tank up and running as quickly as possible.? <Posted... http://www.wetwebmedia.com/FWSubWebIndex/fwset-up.htm and the linked files above> I have? read that I could take water from my existing tank and put it into my fry tank to get the cycling started.? <Yes> Should I filter? out the waste (fish poop, uneaten food, etc.) that I siphon out during the water changes from my old tank? before putting it into the new fry tank??? <Mmm, no, I wouldn't> I'm doing twice weekly water changes with my classroom tank now.? Should I put the old water I siphon from my classroom tank into the fry tank each time I do a water change or would putting it in during the initial set-up be enough to get the cycling started and keep the good bacteria going until the fry tank is needed? <I would use the "old" water for the new tank... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/platyreprofaqs.htm> Thanks! Carolyn <Bob Fenner>

Platies and guppies? Crosses   8/4/07 Hey there WWM crew, I couldn't find an answer to this question on the site nor anywhere else in my books or other online sources, so maybe you can still help me out. The other day I saw my female guppy mating with my male platy, and a female platy trying to mate with just about everyone and anyone. Is this normal first of all? <Mmm, yes... Poeciliids are wanton this way> And secondly is it possible that my female guppy may get pregnant with a half platy half guppy group of fry? Thank for your continuous help! Sincerely, Erica <And yes, can occur... Please read here: http://wetwebmedia.com/FWSubWebIndex/livebrrreprofaqs.htm and some of the linked files above. Bob Fenner>

Birthing without a mate? Guppies   7/28/07 My daughter's guppy gave birth to 4 live guppies on May 20. We purchased her pregnant from a pet store. She was removed from the babies immediately and has been alone since. On July 24 we found 3 new babies in the tank with the mother! There has not been any other fish with her since the birth and I am trying to figure out how this happened? Is this common and is she done? Yikes! <Greetings. Yes, this is normal. Guppies practise something called "superfetation" which means that they can divide up the fertilized eggs into several different batches of embryos. Each batch develops at a different rate, allowing the female to give birth to a succession of broods following a single mating.. Their close relatives the dwarf Mosquitofish can actually stretch this out to no fewer than 6 broods from a single mating! Anyway, welcome to the wonderful world of livebearers! Cheers, Neale.>

Can a fish be "sterilized"? Oh yes... Poeciliids here   7/9/07 This may be one of the more unusual questions you have received to date. I have many mollies that were just fry last September. One of the fish who has turned male is having the same exact tumor problem his father did. The father fish succumbed after the slow growing nodular tumor spread and got in the way of his breathing after several months. One of his son's has been growing a tumor off to the side of his body and localized on the belly, but fortunately not spread to where it would effect his breathing. He still has a good quality of life and is courting his sisters along with the other males. I'd had to separate him since Mollies are a social fish who do well in groups, but I also don't like the thought of him reproducing what appears to be a bad gene. What I'm wondering, would it be safe (and painless) to snip his gonopodium to prevent reproduction? If not, any other suggestions? I don't think he deserves to be put alone or die because of this. Thanks. <Greetings. Sterilising livebearers has been done in the past in the way you describe, typically for breeders to prevent people "copying" their new varieties. Whether it is safe or painless I cannot say, though as a man, the idea of anyone snipping anything off of me fills me with dread! Fish *do* have nerves in and around their fins, as can be seen by the reaction when fin-nippers attack things like angelfish and Gouramis. But your bigger problem is what to do with the male. Personally, I'd isolate him. Put him in a tank on his own with (ideally) other brackish water fish. Mollies are not really schooling fish, so while they enjoy company, they don't pine away from the lack of it (unlike, say, Neons or Corydoras). You are absolutely right to try and remove poor genes from your stock. Whether a tumour is actually genetic though is a different question. While they can be, in many cases they are caused by other factors, such as viruses. In female livebearers they also seem to be caused by certain problems during gestation. But if it is genetic, there's no reason to assume only the male carries it; genetic disorders can be carried by females even if they don't express them. I'm sure you recall from biology class at school how Haemophilia works, for example, which is a human disease that can be carried by females but usually manifests itself only in males. In other words, when you breed the next generation from your females plus some new males from elsewhere, don't be surprised if you see this tumour reappear (if it is genetic rather than caused by something else). Cheers, Neale>

Re: Can a fish be "sterilized"?  7/10/07 Per the below advise, I will go ahead and just separate Jack Jr. (fish with the tumor - they all have names). Would a 1 gallon tank (aerated and filtered of course) be enough for him to live his last days out in? (I don't have a separate tank avail, so they just reproduce in a 55 gal and babies live by hiding in the abundant plants an decor. <No, a 1 gallon tank isn't really acceptable for a molly. At some point breeders have to euthanise unwanted fry. Fish produce too many offspring to care for them all, especially if they're "faulty". But that's your call.> On coloring for mollies, I seem to have a blend I have not seen - I have a few that are a deep beautiful orange color on the body, black dorsal, side and tail fins and pure white belly. I have not seen any in pictures with quite this variety. How common/uncommon is this color pattern? They almost resemble a red-wag platy color-wise. I read up that fish can change color to a degree associated with mating; would this be the case, or have I lucked out on getting a somewhat unique color scheme? (The fry came out of gold dust mollies) <I have no idea whether such a variety is new. Creating a new colour variety isn't difficult, but getting it to breed true (i.e., the same, generation after generation) is much more difficult. Same as with breeding any animal. Your regional livebearer club (e.g.. American Livebearer Association or British Livebearer Association or whatever) will probably be your next stop if you're serious. As well as having a club you can join to discuss with other experts, they will have auctions and meetings where you see and learn about livebearer breeding. Mollies generally do not change colours in the same way as, say, cichlids. Good luck! Neale>

Re: Can a fish be "sterilized"?  7/10/07 Thank you again. I think at this point I am seriously considering euthanization in light of the tumor growing so that he does not die a slow or painful death. I think I'll just keep my fish as a hobby for now, but thank you for letting me know there are organizations for livebearers and such should I ever get more serious down the road. Have a wonderful day! <Glad to help. Cheers, Neale.>

Male guppy romancing female platy    6/5/07 Hi, <<Hello, Krista. Tom here.>> I have a male fantail guppy that is exhibiting mating behavior towards one of my female platys. He follows her around, snuggles up next to her and swishes his tail in her direction. <<A Guppy lounge lizard, eh?>> She is not interested and is constantly trying to stay away from him. <<You've raised her well, Krista. :) >> Can they crossbreed? <<I've run across unverifiable accounts of Guppies cross breeding with Platys but find these reports rather doubtful. Platys with Swordtails? Yes, but not Platys with Guppies. Livebearing females can store the males sperm for a period of time resulting in multiple births from a single mating. This occasionally gives rise to accounts from hobbyists that a female Platy, for instance, became pregnant by a male Guppy. Doesn't take into account that she likely mated with one, or more, male Guppies at the LFS before coming to her new home. A far more likely scenario, in my opinion.>> What is the likelihood that she can become pregnant by him? <<Again, in my opinion, none.>> I purposefully have all female platys (3) and 2 male fantail guppies because I didn't want babies - my tank is too small (4 gal BiOrb). <<In a tank this small, its barely possible that fry from viable parents would escape being eaten by the adults anyway, Krista. Nothing cruel or heartless about this. Simply the natural way of things.>> Thanks, Krista <<You're welcome. Tom>>

Hello, FW livebearer info.   5/10/07 Hello guys,   (From Andreas, Cyprus) <Greetings from San Diego, California>      Great website guys, i just found it out and there is endless information.   I have tried to search for my question to your website but i didn't manage to find anything.   My question is how old the female balloon molly and female guppy has to be to be able to get fertilized and give fly? <Only a few (three-four) months really>   Also how old males has to be to be able to fertilize the females? <About this amount of time also>   Just for information in my tank i have 3 balloon molly, 4 guppy, 10 tetras, 2 angels, a Pleco and a Kuhli loach. And 47 balloon molly fry and 6 guppy fry. The fry is currently in breeding net, unfortunately i can't let them free yet in main tank because of the angels, even thought my angels are not so big they would happily eat them all. I'm thinking to get rid of them but they are really good looking so i don't know yet what to do) <Perhaps another aquarium for the angels by themselves...>   anyway I'm going to make another small tank soon for the fry to grow, so maybe that would solve the problem.    <Ah yes>   Thanks. <Welcome my friend. Bob Fenner, who was out in Cyprus in '96 for the Hash House Harriers Int'l runs.>

Breeding grass on top or bottom? Depends on species   4/24/07 Thank you so much for your website! I have spent many hours there and have learned a lot! <Good> I have a 10 gallon tank with platies and one is definitely pregnant. I bought some plastic aquarium breeding grass today and was wondering if it is better to let it float on top of the tank or anchor it in the gravel at the bottom for the upcoming fry? <Near the top for these livebearers> I was concerned if the fry would get enough crushed flake food if living in the grass on the bottom. I suppose I could cut the grass and let part of it float and put part of it on the bottom? Thank you so much! Michele <Welcome. Bob Fenner>

Swordtail guppies?  4/10/07 Hello again, I've been sucked into your website :) And I have another question I can't seem to find an answer to. Can you breed swordtails with guppies? Because the third fish in my tank is a male guppy (with a female swordtail and a male molly) and, while the molly has been mating with the swordtail only occasionally, the guppy won't leave her alone (yeah those guys are insane). So I was wondering, with all that action, could I end up with swordtail guppy mutant babies? :P Thanks, Didi <Possibly. BobF>

Superfetation  3/30/07 My son bought a female guppy nearly two months ago, and within the first week she had 8 babies. She has been kept in a tank by herself for the time since, and yet she just had three more babies tonight. As they are live bearers,  I am not sure what is going on, and I came across the term superfetation, and  wanted to know exactly what all this meant? Will we have any more babies to deal  with? <Mmm, plainly put, this is the capacity to store viable sperm in (this case female guppies') reproductive tract. A useful strategy for when it "takes two to tango" and there are no males about. You may indeed have more young from this "lone" female. Bob Fenner>

Run-on Sentence & Livebearers 1/23/07 Hi <Howdy.>     I have a female Hi-Fin orange swordtail, and it was never pregnant, <Oh.> but I did have a male swordtail, but it has been dead for a month, <Ahh.> and I have three guppies two that are trying to mate with it and I can see they have a few times from what I noticed, and now it is pregnant, so I had wanted to know, is it possible for a swordtail and a guppy to mate? <Yup.> and have a fry? <You betcha. http://www.wetwebmedia.com/FWSubWebIndex/livebrrreprofaqs.htm > <P.S. This email is made up of two sentences - one with four word, and the other with... over 50. While not absolutely necessary to make your point known, it is considered rude by myself and many other crew-members to have to field questions that have so obviously been spun-off and sent before any proof-reading at all. Consider this your ONE freebie from me. In the future, if you don't want to take the time to make your email presentable for display on our dailies, then I won't take the time to answer with any more than, "Please resend in proper grammatical English, please." Graham T.>                                                                 ~Thanks Louis~

Ich and Fry, FW livebearers     1/14/07 Hi there.  I'm completely new to this site (within a week, at best) and it seems to be an amazing site for answering questions. <We do try...> Here's my question... I'm a fairly seasoned "fisher", though this is one problem I've never encountered before.  I recently purchased some Red Wag Platies (sp?), about two weeks ago.  They are in their own tank (separate from my non-livebearers).  I just noticed their BRAND NEW babies this evening upon returning home from work.  I was just now over checking the progress on my new babies, noticed one more (rather exciting for someone who usually keeps tetras...lol).  I then started really watching the adults trying to figure out which one was slowly giving birth...... and that's when I noticed it..... ICH!  On at least two of the adults, it's visible. <Oops> My question(s):  How do I treat a tank with fry that are still so new? <Mmm, better to separate... take out the adults, treat them elsewhere> I've seen a lot of posts about aquarium salt, and Ich meds and the likes.  I currently have on hand (just in case) what's called "QuICK Cure", the active ingredients being Malachite Green and Formalin. <Yes... quite harsh> Should I medicate the tank with the new babies in it?  If so... should I be removing the carbon from my AquaClear Filter for better medication?  Basically, I'm not sure what to do because of the fry... I'd really hate to lose my first hatch (however... being a reasonable and educated person, I do realize this a good possibility.  Just want to prevent it, if I can). Any advice you can give would be greatly appreciated! Steph <I'd move the adults and treat them elsewhere. BobF>

Plans for livebearer fry in community tank; male dwarf Gourami bubble nest   12/19/06 Hi Crew, <Hello - Jorie here> Thank you for a very quick reply to the question I <I; please use proper capitalization, punctuation when writing in...I've edited this one, but would appreciate not having to do so next time!> had about my female guppy being pregnant and swimming funny.   <Don't think I answered that one, but I'll try to help with this one...> I have now done a lot of research into guppies and the other fish I have in my tank, <Excellent - that's how we all learn> another female has had fry today, <Yes, livebearers will do that when males and females are kept together in community tanks...> that's me <??> now got <have> 25 fry (very proud!! Although it is said to be easy to do, I'm still very proud) <Congratulations! The harder part is keeping them alive and healthy...> The only problem is, I did not plan to breed but this is life and I do not want to stop it from happening, I cannot have two fish tanks in my house, so I bought a breeding net to keep the fry in, I also need one for the female. <Well, if you cannot have any more tanks, then why are you trying to isolate the fry and mom, so that she can give birth to even more young? First off, female livebearers can store sperm for up to 6 mos. I am told, so even if you isolate her now, she'll like continue to give birth to new babies every 4-6 weeks.  You'll soon become overrun with fry! I understand you don't want to hurt the fry, but I imagine you'll not want to add to your "collection" if you have no ability to add more tanks; you'll very soon become overstocked. Second, I am not a fan of breeding nets at all, as it is my view they tend to unnecessarily stress the fish out.  If it is your intention to raise the fry, providing plenty of cover (in the form of plants, especially floating ones, and decoration) in a community tank will allow the fry plenty of places to hide from predators.  Also, it will allow the mom to hide while she's giving birth as well. As cute as they are, livebearer fry will ultimately run you out of house and home...I've invested in several new tanks just to accommodate my young mollies and platys.  If you aren't prepared to do this, best to allow nature to take its course and have larger fish in the community tank feed themselves on the fry.  It's nature, not murder...> Is there any other way to do this as the nets are blocking the rest of the tank. <Ditch the nets. Nothing good will come of them - as mentioned above, they'll likely stress out the fish.  Also, if you don't have room to keep/raise the fry, best to let nature take its course now while they are little...> I think some info over my tank would help: I have a 160 liter, well planted. I think just need to work on cover plant for the fry, <Java moss works well> gravel based with a large ship as deco. I have enclosed a picture; don't know if it is any use. <I always like to see pictures of peoples fish and tanks!> If you would like to use it feel free - this was at the start <For some reason, I wasn't able to "reply" as I normally do, to your e-mail, but rather I had to cut and paste the text into a new message.  I wasn't able to save the picture, unfortunately.  But I do appreciate you sending it along and I enjoyed seeing it!> Any way the main reason for writing was to thank u for taking the time out to answer me. <As I said before, I don't believe I answered your previous query, but on behalf of that crew member, you are welcome.> No doubt <doubt> I will have many more questions to ask you as like u <you> said every day is something new. <That is true, and we are here to help.  But, please do look through the wonderful articles available on www.WetWebMedia.com ; also, there's lots of other useful websites, books, etc. out there to be discovered...> I am currently reading up on Dwarf Gourami, as I think they were trying to breed. The male started to build a bubble nest but nothing came of it.   <Sometimes when male fish do this, they are simply showing the females they are ready to breed...no worries, no harm.  They'll breed if/when ready!  Also, these fish will likely keep your livebearer fry population in check...> I have searched my tank from top to bottom, and to be truthful I did not know at the time what the male was doing till I researched some. <The beauty of reading, research...> Once again thank you. <You're welcome.  Hopefully I've helped you with your livebearer fry question/"dilemma". Best regards, Jorie>

Swordtails Breeding with Mollies?  - 10/24/06 Hi from Australia <<Hi from the USA. Tom here.>> I have a large 3 foot aquarium that has a silver shark, lace Gourami, 3 female mollies, 2 female swordtails, 2 mail swordtails and 2 large silver dollars. I also have a small tank that has about a dozen swordtail fry born only yesterday. <<Congratulations.>> I have two questions that I hope you will be able to answer. <<Ill give it my best>> Firstly, I just guessed when I thought that the swordtail was pregnant (these are my first fry) and put her in the breeder tank because everything I read says that you will know that they are about to have the fry when you can see their eyes at the back of the belly. <<A very good indication, certainly.>> My 3 females all have black stomachs and I can't see anything, is there any other way to tell as I think the other two may be pregnant as well? <<Early in the pregnancy, this may be a little difficult particularly when the gravid spot isn't clearly visible to you. Obviously, as things progress the abdomen will become fuller/rounder and, when time for the blessed event is near, the female will tend to isolate herself from her tank mates. One common behavior is for her to linger near the aquarium heater if one is provided. Her vent may also become a little more pronounced.>> And, I think that 2 of my mollies are pregnant. Is it possible for swordtails and mollies to breed as the mollies were given to me as fry and I have had them for months so I know they weren't pregnant when I got them? <<Yes, this is possible. Its a bit of a misconception that livebearing fish like Mollies, Swordtails, Platys and the like will readily crossbreed but it can/does occur. In general, each will seek out its own kind first but, in the absence of this, males of one kind may seek out a female of another variety.>> Please help. Thanks Amanda <<You're welcome, Amanda. I hope all goes well. Tom>>

Livebearer gender question:  Want females......but........   8/21/06 All I got was males. <Odd...>   I'm referring to my baby platies.  I know that a previous question has been submitted by someone about temperature affecting the gender of baby livebearers, but it seemed inconclusive.  I would really appreciate any information.  I have a new batch of baby platies and I really want to know if there is any way that I can make most of them turn out to be females. <Mmm, not really... cooler water temperatures, frequent water changes for the adults might help...> I want to selectively breed them, so I need females.  I appreciate your time and advice. -----------------------------------------------------Heather <Not possible as far as I'm aware. You might want to peruse the American Livebearer Association's site re. Bob Fenner>

Poeciliid Fry growth    8/7/06 Hi there, I have a few questions for you. I was wandering <And wondering?> how fast do fry grow and how many weeks till you can start telling them from female and male? <Mmm... for most livebearing species a few weeks... 3,4,5 will serve here... can be sped up a bit by frequent small feedings, and changing parts of the water on a regular basis (reduces metabolites that slow growth...)> We bought our first set of mollies on the 5th of August. She started to have babies in the bag on the way home.  The man at the store said she would have about 30 fry, well we got home and put her in a bucket and she had the babies in a 10 gal. aquarium.  After a hour past I checked on her and counted all the babies as I moved them and she had a little over 100 fry.  Now my next question is the next time she has fry will she have more than that or about the same amount?  I sent a picture for people to see the difference in a male molly. Thank you Robin <Mmm, thank you for this. Please read here: http://wetwebmedia.com/FWSubWebIndex/mollyreprofaqs.htm and the linked files above... Much more pertinent info. to relate... and you'll realize the "method in our madness" in such referrals. Bob Fenner>

Livebearer, Platy Repro.   8/2/06 Hay <?> I have 5 platy sunset and 5 platy red and 2 rosy barbs. I want to know will the platys red and sunset will mate and have babies. Also how do I tell what sex they are? And what do I do with the babies?     Thanks matt <These platies will cross-mate (are the same species, just different "breeds", like domestic dogs). Please read here re: http://wetwebmedia.com/FWSubWebIndex/platyreprofaqs.htm and the linked files above. Bob Fenner>

Breeding different livebearers...   6/16/06 My main question here is if it is possible to breed, say, for example, a platy to a mosquito fish.  Since they are both livebearers, I wondered if they could create hybrid babies.  Is it even remotely possible? <Some Poeciliids do readily crossbreed... e.g. Platies and Swordtails... others not as surely> I have recently become interested in selectively breeding platys in an attempt to create a new variation or type of platy. <You're in good company. There are a few folks, groups that have this as an activity>   In having plenty of offspring, I was wondering what would happen if I bred a male platy to a female mosquito fish (as I already have 24 mosquito fish babies, I intend to separate the males from the females as soon as a difference can be determined).   <Mmm... don't know that you want to go this route... Gambusia, Heterandria species are not very attractive to start with... will take quite a while, generations to return much in the way of color, finnage> I'm not too experienced in genetics and I don't know if the two fish would even take an interest in one another, but I heard somewhere about platys being able to breed with swordtails and maybe guppies, so I would appreciate a confirmation on what is possible.  Thank you for taking the time to read my question.  I would be very happy if your crew could answer this soon.   Thanks again!! :) <Interesting speculations. The most useful expenditure of your time will almost assuredly be going to a large college library (with a Bio. dept.) and having a reference librarian show you how to devise a search strategy... computer based bibliography on the genetics, breeding of Poeciliids. Bob Fenner> Re: Breeding different livebearers...   6/18/06 Well, you do have something there about mosquito fish being a little unattractive.  I find them a bit charming, though, so it balances out.   <Good! I have bred all of these...> Plus, there is an interesting story behind how I obtained my two mosquito fish females who are currently pregnant................ again.   They were swimming among "feeder" goldfish in a crowded tank. <Often mixed in for mosquito/vector control...> When I saw that one of the two was really pregnant, I knew I had to at least buy her for the sake of saving some of her offspring.  The other female was hard to resist since I found out the cost for each fish would be nineteen cents.  So I saw it as my "forty-cent bargain".  Long story short, the 24 baby mosquito fish that I have now are all from the female who was heavily pregnant at the time I purchased her. Knowing now that mosquito fish are usually a little on the undesirable side, I happened upon the thought to cross breed them.  I give thanks, once again, for the fine crew at wet web media's quick reply.  It was much appreciated.  I could attempt the platy cross breed, but, since the results are inconclusive and unknown, I came to wondering if breeding a guppy to a mosquito fish would be a more likely success.  Of course, breeding mosquito fish isn't my main motive in selectively breeding fish.  The platies are going to be the main production.  I would just like to do something with my new mosquito fish fry, especially since there will be more on the way.  I would appreciate the answer to the question of whether or not a male guppy will breed with a female mosquito fish, as it is the last question I have on cross breeding pairs. By the way, I will try to look into a college library at some point as I am beginning to think that a stronger understanding of genetics will be necessary in my projects and fish breeding activities.  Thanks again!! <Please do report back. I don't recall off-hand whether it has been reported that these Poeciliids have produced viable young from crosses. Cheers, Bob Fenner>

Re: Breeding different livebearers...............  6/20/06 Okay, I will report back with whatever results in a cross breed.  It will be a while, though, since my mosquito fish fry are only a few weeks old. <Ah, yes... takes multiple generations... years> Once they are old enough to tell male from female, I will separate the different genders from each other and continue to raise them to maturity.  When I have a mature female, I will introduce her to a male guppy and see how things work out.  Even if I get them to breed, it will be a while raising the babies to finally have a clear result. Still, I will be sure to report as I figure things out.  Hopefully we all have the patience to see this through!!   Well, I do thank you once again and I will keep your crew informed on this project. <I/we thank you. I encourage you to keep good notes, possibly write up your experiences for the ALA, other media. Bob Fenner>

Breeding different livebearers... platy gender concerns    7/13/06 I would like your crew to know that, since Mosquitofish are very similar to guppies, they can crossbreed. <Thank you for this> A person at an experienced pet shop mentioned that Mosquitofish are, basically, just plain looking guppies and the two species will crossbreed. <Mmm, actually, there are a few Poeciliid species commonly termed "Mosquitofish/es"> Although, the person doubts that any really interesting offspring will result at first. I thank you for your replies to previous e-mails.  As I have raised my livebearing fry, I came up with a new question.  Since I plan on selectively breeding my platies, among other fish, I wanted to know how to determine their gender as early as possible. <Mmm, really just keen vision, observation... gonopodia and behavior>   I am wondering whether or not a female platy will have a slight extension on the anal fin by the tip. <Yes... the first ray or two...> And I'm saying very slight.  I've always heard that females will have fan-like anal fins, but is it possible for a female to have a more pointed fan type of anal fin.  As I am saying this, I want you to be clear of what I am picturing.  The fish in question's anal fin spreads out like a fan, but its tip is slightly (and I mean slightly) longer than the rest of the fan-like fin.  This tends to make me wonder since the earliest form of a male's anal fin is usually the fan-like shape becoming more extended and pointed. <Agreed> I really don't want to mess up with this, so any help would be appreciated as to how to correctly determine a male from a female at their earliest development.  I'm shooting for a way to be able to completely prevent any breeding between siblings. <Early separation... the first few weeks...>   I really wish I could keep each little one separate, but that would be very difficult to do- since I don't have the kind of money to be able to provide separate containments for each of 10 or more offspring.  Thank you for taking the time to read my question/concern. <Thank you for writing, sharing. Bob Fenner>

My livebearers don't seem to be breeding   2/7/06 Crew: <Tim> I have a cycled 29 gallon tank that has been up and running since about October.  I lost a few fish early on when the tank was still cycling but everything has been fine since then.  Currently my tank is a little overstocked but the fish seem healthy. I have 3 platys, 3 swordtails, 3 green Corys, 6 lemon tetras, 8 zebra Danios, one small bushy nosed Pleco and 2 small clown loaches.    Of the swordtails, one is a male and two are female.  Of the platys at least one is a male and one is a female, but I have trouble telling for the third platy.  It looks like a male but I can't tell whether it is just pulling up its anal fin as it swims.  I also have a number of plants. including java fern, java moss, Cryptocorynes, Ludwigia, Cabomba caroliniana, Hygrophila, Amazon sword, hornwort and Anacharis.  Some of the hornwort is floating at the top.  I was having some trouble with rams horn snails getting out of control but not anymore since I introduced the loaches.   <Ah, yes> (There are still snails but not too many).  I have not added any salt for the sake of the plants and the tetras. <Good>   The temp is set 78.  The ph is fluctuates between 6.8 and 7.0, the carbonate hardness is 3-4, and the GH is 7-8.  I have two 2 bulb t-5 strip lights that provide a total wattage of 72 (4 bulbs at 18 w each).   I have algae but it is under control since I adjusted the timers to turn the lights out for 2 hours during the middle of each day.  I'm adding co2 regularly using one of the low tech plastic gadgets where you add the fizzy tablets.       <Sounds like a very nice set-up, livestock mix> To the best of my knowledge the platys and swordtails have not had any fry.  They seem to be engaging in courtship behavior.  Is it possible they are having fry and I have not seen them before they are eaten. <Yes, most likely here> How can I tell if the female is pregnant?  Any ideas what I can do? Thanks.   Tim <Mmm, the general "roundness" of females, their more hiding/slower moving behavior, the darkening of the vent area are all indications... quite "pregnant" females can be moved in advance... to other systems, a breeding net/trap... but young may cause crowding issues here with growth... I would let "nature take its course"... unless you have other tanks, intend to give away the offspring. Bob Fenner>

New fry and tank care  - 03/13/2006 Hello WWM Crew:     I very much appreciate all your information and support.  I have written a couple of emails recently and have found great comfort in your replies and advice!  Thank you!!  My 3 1/2 daughter, Katee, has recently had some new additions to her fish family.  About four days ago her Mickey Mouse platy, "Sunshine," gave birth to 7 babies.  I was able to retrieve 5 right away and place them in a breeder's net within the tank.  Her tank is 16 gallons containing a total of 4 male guppies, 1 mm platy, 1 red platy, 1 silver platy, 1 baby black molly (given to her from the pet store about 4 weeks ago), and a dwarf Plecostomus.  Today we found 2 more babies swimming around the tank, retrieved one and put it in the net.  The last is still in the big tank. now named "Houdini."  I noticed that the tank near the net is growing algae...I am trying to keep it clean by sucking out the waste with a children's medicine dropper and I also use it to clear any uneaten food after 20  minutes.  Is this the best way to keep it clean? <Perhaps a length (five, six feet) of flexible airline tubing fashioned as a siphon would work best here> Any additional ideas?  How is it possible to do a water change if the fry are hanging at the top? <Careful siphoning> Do I even want to do a change? <Yes, some every week> I made a 5 gallon water change last Monday and added the required salt at that time too. I have been prepping my daughter that not all the babies might make it, but so far we have a 100 % success rate.  How many fish can her tank support? <About this many when fully grown> I am attempting to keep this tank as low maintenance as possible, is that asking too much?   <Mmm, no> We do have a place some of the babies can go to at school, a very well maintained 20 gallon tank with only 6 platys.  How long do the fry need to stay in the net? <Till more than mouth size...> Is it better to leave them there or let them be free...."Houdini" has done very well and he is the smallest.  Currently the fry are being fed 3 - 4 times a day with "first bites" and the others get flake food each evening.  Should I maintain this schedule? <Yes> For how long?   <A month or so> Thank you very much for your attention to this matter.  Both Katee and I are extremely grateful for your input.   Sincerely, Debby <Welcome. Bob Fenner>

There's something in the water...  - 03/11/2006 Hello all,     Thank you very much in advance for your expertise.... <Glad to share it> I am very happy I found your web forum, I have found it extremely helpful.  My 3 1/2 year old daughter is obsessed with fish!!! <Do sneak in the occasional spread sheet, business tome...!> We have a lot of exciting things happening in our 16 gallon tank.  We recently have had 5 new Mickey mouse platy additions to our family, they are happily residing in a breeder's net and eating well and are very active, even the tiniest of them all.  Unfortunately the "Mama" broke her back during birth and had to be put down (it was a happy and sad day yesterday!)  Now that I have taken a deep breath I believe that the red platy and another platy in the tank are pregnant too!!!  This tank has now 5 fry, 3 Mickey mouse platys, 1 red platy, 4 male guppies, and one dwarf Plecostomus.  From surfing your site I see dark areas on the lower parts of their bodies.  Do the fish show any other signs before giving birth? <A clearing of the distal vent area... a day or so ahead... and "hiding" behavior> The red platy is being slightly piggish at mealtime and chasing off the others, while the yellow Mickey mouse is hanging back and down in the plants.  How many fish can my tank support? <Mmm, "well"... depends on size, maintenance... but a couple of dozen... a good idea to "share the wealth" here... with the growing of young, to give these out to others that want them> Do I let these new ones fend for themselves? <This is one way... and in general best, yes> There are lots of hiding places in our tank, many plants, large pebbles, rocks etc.  How many fry can go into the breeders net and not be over crowded? <... depending on size... a dozen or two...> Should I get a second one? <If necessary, yes... and/or keep an eye out for sales on new/used tanks/systems> Can you place multiple fry from different "Moms" into the same net? <Yes> Thank you for any advice you can give me.  All is helpful!!     Katee also has a very happy 5 gallon tank that has never given an ounce of trouble.  On the other hand her 2 1/2 gallon tank smells sulfuric. <A very common trend for "too-small" systems to have/be trouble...> At one time it had black slimy algae growing in it, but I replaced all the plants with new ones and it has not returned, except for the smell.  Any idea? <More aeration, moving (during water changes) new water for the tiny tank from the larger ones... time going by> This tank only has 1 fish a two inch red-eyed tetra named "Poop."  Can this tank support any more fish? <Of some species yes> Thank you again.  Have a wonderful day.  Sincerely, Debby <Thank you for writing, sharing. Bob Fenner>

Platys and Mollies  - 03/05/06 Ok first I want to say HI! Then I want to apologize in advance for the simple questions I am about to ask. Ok I just got two mollies of some unknown variety and the same with two Platys. I really want babies now that I know they are live bearing fish. I am extremely new at this for I have a one gallon tank don't know anything about hard water, soft water, brackish, nitrites, and I have them in a tank with water from my sink. I'm sure right now you are thinking "oh great"! Well I REALLY want to get into breeding these fish but I'm not sure how to tell their sexes. <Not hard to do... they have internal fertilization (as our species does)... males have modified anal fins, gonopodia, for genetic intromission... gone over on WWM> OK if that's not bad enough here is the worst thing these are Wal-Mart fish! Anyways I know that males have a gonopodium but I can't really tell if any have this. <Oh! May be too small to see at this point> I have one black and white platy, black back with white fins and belly and semi iridescent black scales, who always keeps its anal fin tucked ,i hope to god that was the right name, I am almost positive that its a he. The other platy is smaller by just a little bit and is bright orange with yellowish fins I am sure this is a female because that fin is always out and look round but she is smaller than the other. Aren't males smaller? <Yes> The mollies are what I am most concerned about. One is yellow with kind of iridescent spots. The other is larger and has a yellow color with orangish and black spots. This one seems to be dominate over the other it seems that it chases yellow one about until she feels satisfied about her position in the tank. I am not sure if they are both female and I don't know if they are okay where they are now they seem to be fine i think except for the chasing between the two mollies I think they both might be female , and that is okay for now I suppose. Later today I should be going out and getting some new fish and my friend is giving me another ten-twenty gallon tank. <Much better... the present one gallon is too small, unstable> I broke the first one he gave me within the hour of getting it, I dropped it in the sink while trying to clean the hard water out of it. Well I need to know what to put in this new tank. Currently I have rocks, one fake plant, an air pump, and a thermometer. I got from my friend a filter, a thermal something and a light for the top of the tank but I don't know how to use any of these things. <Posted on WWM... but I would have a "fish friend" come by and help you in person> I think the mean female molly is pregnant she has that dark spot in her belly how can I tell when she will give birth? How many fish can fit in a ten-twenty gallon tank? <Both posted...> I must know so I don't over fill it especially if their are babies on the way. Ok well the platys seem to be right at home just swimming about but the mollies hide by the plastic plant in the tank a I put bulbs for a plant called an Aponogeton is this an okay plant? One more thing I feed them regular fish flakes is that okay? How often do I feed them? Thank you for your help I hope this is better Maria <Please see WWM. Your answers are there. Bob Fenner>

Baby Molly and Pregnant Platy   3/3/06 Hi, I have one breeding net it has one baby Molly in it is it ok to put a pregnant platy in with he baby Molly ? <Should be okay... if the molly is large enough... more than mouth size. Bob Fenner>

Re: fish fry stuck in mother Thank you very much. <Happy to be of some help.> So if they don't come out does she die and the fry live? <If the egg material isn't reabsorbed into the female's system, which is typically what we'd expect, yes, it can be fatal to her. Once born, the fry are going to be reliant on you, not "Mom". You might try adding a small amount of aquarium salt to the tank, on the order of one tablespoon per 10 gallons. I've no first-hand experience with using salt for this purpose but have run across this suggestion during other research. Good luck. Tom> Everett

Tiny Tank With Fry On The Way   4/30/06 I have a 5 gallon tank with 2 swordtails, 4 mollies, an Otocinclus and 3 small shrimp. My silver molly is pregnant, will she come to term in such a small tank? Also, I do have a few live plants but will the fry survive? I am not sure if it will be too crowded and effect the other fish. Thanks! <Hi, Don here today. Yes, your Mollie will give birth in this small tank. I would think that most will be taken by the swordtails if you leave things as is. This is not a bad thing, it's nature's way. But if you want to raise the fry and keep the fish you currently have, you will need a second (or larger well planted) tank. You are already overstocked, the fry will put additional stress on the system. Look into setting up a 20 gallon long for your current fish and using the 5 as a fry and shrimp tank. If a new tank is not possible I suggest you pick your favorite 2 or 3 fish and find new homes for the rest.>

Freshwater 20g... unexpected surprise...  - 04/27/06 Hello... and thanking you already for any help/advice you can give,    I've been searching your site but haven't been able to find exactly what I'm looking for so I do apologize if this type of issue has already been addressed and I just couldn't find it.    I recently bought a 20g tank for freshwater fish. I am very new to this hobby and mistakenly took the advice of the PetSmart salesperson - I didn't know a thing about cycling until stumbling across your website. I did purchase a bottle of Cycle and have been adding as per the directions but no one at the shop told me not to add the fish right away. <A very common mistake... often deadly> My bad for not investigating further.  I've had the tank for almost three weeks and so far the fish I have are doing alright - I have 5 platys and 5 mollies. They're "happily" swimming and eating and there don't seem to be any problems ( please keep your fingers crossed for me :) ). Here's my problem  - I specifically asked for only male fish because I didn't want the possibility of having fry until I became more accustomed to taking care of the adults if that makes sense. Well, lo and behold I now have eight fry ( three of them I noticed last week and the five new ones I noticed three days ago - the new ones are still "baby babies" ). This is my question ( finally :o ) - I would like at some point soon to get into the tank with my gravel cleaner, how safe is it to do so with these babies hiding everywhere? <Not generally a problem. They avoid such> Secondly, since I biffed the cycling process should I wait awhile before cleaning the gravel in an effort to not create an even larger problem? <Yes... you are wise here. "Cycle" (Hagen product) does often fail or not work in the first place. I'd wait another month or so before changing water> Thank you again... it's so very very much appreciated!! Geri       <Welcome. Bob Fenner>

Livebearers Dear Robert, one of my swordtails, female, has recently 'built up' some black dots and marks in the area from the eyes all the way back to the dorsal fin. This is not maturity as it was already mature. How do i tell if it is pregnant? thanks >> Hmm, well the black spots could be "nothing", at least nothing dangerous... melanin build up from genetic, developmental input... The pregnancy, close to parturition (birthing) is a matter of having good vision... Take a look near the fish's vent... as it gets near to releasing its young, you will see the area enlarge, become clearer and the eyes (little dark spots) of the young themselves, a few days ahead of release. BTW, do take care to not move the female (as in to a breeder trap or other tank...) in later stages of pregnancy... instead, I suggest placing enough filamentous bunch plant material (like Myriophyllum, Hornwort, Anacharis...) for the young to hide in. Bob Fenner
Re: Re: livebearers
Dear Robert, so i should not use the breeding trap? <You could/can if it's big enough and you move the pregnant female(s) ahead of giving birth a few days or more> Is the vent the area near where the fish excreta is released?  <Yes> There is a pink spot there right now and that sword is becoming fatter by the week. Will that pink spot become black in colour? <Yes, with the develop of the young, you can actually make out their eyes as they get larger... and the vent region will become whitish/clear.> What behaviour signs can i look for to tell that my fish is ready to give birth? <Less movement, more hanging out at areas where the young could seek shelter.> BTW do you really think that those black spots on the head are just the fish maturing?  <For the most part, yes> When my platy gave birth it didn't develop them. My platy was hiding from everyone else but my sword doesn't do that, does it just mean that the fish isn't ready to give birth yet. >> <Possibly. Bob Fenner>

Re: Livebearer Swordtail Pairs? will now i got the female and the male pineapple swordtail fish in a breeding tank with a net how do i know that she pregnant in the other tank i saw little black dots like they said you will see but they also said that the fish don't take more than 24 hours to 2 days to lay their hatchling but i don't see them in the tank do the female waits to have her young or do she have them at any given moment? <Any moment now... depending on a few factors... the higher the temperature the sooner for instance. Bob Fenner>

HELP!!!!!!Female Guppy Two days ago i purchased a female guppy, today she gave birth to 15 fry. I had her in a fish net breeder that you attach to the side of the tank, whilst she was giving birth. Every time a baby came out i put it in a fish bowl. when she had, had them all i put her back in her original tank. i then put the fry into the fish net breeder, at the moment they are just sitting on the bottom of the net. the are all alive because if i move the net they swim back down to the bottom, Why are they staying at the bottom? <Likely just from the trials of being born and being moved... Next time, either leave the female in with her young till they're all out, or look into one of the types of traps that "automatically" separates the young. And do utilize some sort of real or artificial "breeding grass" (Anacharis, Myriophyllum, Ceratophyllum...) in with the gravid female. Good luck, and congratulations. Bob Fenner>

Platies and Guppies I recently purchased 4 platies 1 of them is very fat and she stays in the plants and on the gravel a lot, do you think she is pregnant? Also i have 4 Guppies, 2 males and 2 females, I want to breed them, how can i tell if they are going to breed, what are the signs i should look out for? Also i would like just one Siamese fighting fish but will it attack my guppies? Please, please, please email me back A.S.A.P at Thanks for the help. from Alex <Thank you for writing, and yes, it is likely your platy is indeed going to give birth. Take care not to move such fish when they are very gravid (close to parturition), as you can gauge from their girth as well as a clearing near the females' vent areas (if you look very close, you may be able to see the young's eyes!) at this time. As I say, it is best to have plenty of room, some plant material for the young to hide in (lest they be eaten by the other fishes), and keep their tankmates fed (small amounts at least twice daily). A Betta, aka Siamese Fighting Fish would likely chase your fancier male guppies (their fluttering tailfins are irresistible) and would definitely eat your young livebearers. However, you could easily house the Betta in a container within your aquarium, like a glass hurricane lamp cover or attached plastic trap for the purpose... effectively keeping them separated. Do keep in mind that Bettas need regular meaty foods (frozen/defrosted, fresh, live) to stay healthy, and access to the tank surface to breath. Bob Fenner>

More on Pregnant Platies I forgot to bookmark your web page and i cant find the site could you email me the address? Also how can i tell if my platy is gravid? Please email me back at sparkle Thanks <Our URL is WetWebMedia.com, and your female platies are gravid (near to giving birth) when they're apparently more full, and their vent area (the underbelly just behind the anal fin) starts to become clear. Bob Fenner>

Guppy, Pleco Q's Hi, I was wondering what is the shortest length of pregnancy for a female guppy? Also What age does a female guppy reach sexual maturity? Also i have a Pleco and i bought it when it was small but it grew fast now it is starting to get too big what should i do with it and will it start eating my other fish? and what could i get that would clean my tank but not grow very big? thanks Alex <About a month... about four months... trade that too-large Pleco in at your fish store... not so much that it will harass your other fishes, but may starve, knock everything over... How big a tank? Read over the Suckermouth Catfish article posted on the www.WetWebMedia.com site. Bob Fenner>

Poecilia Bob, Hi It's me again, Brenee King, a student of Mr. Nordell's I wanted to know how Poecilia latipinna and Poecilia sphenops can mate even though they are different species? Or was I mistaken about their mating capabilities? Brenee King <Hello there. Rather than just rendering yes/no responses here, let me send you along to www.fishbase.com where you can/should insert the genus of these two livebearing toothed carps and click below on "reproduction"... Some strange goings on, challenges to "species-concepts" with the families of livebearing fishes... Be chatting. Bob Fenner>

Platy gravid spot Hi... Been searching high and low for a picture of a pregnant platy. I think mine might be expecting, and keep reading about a gravid spot to confirm it , but am not quite sure what i am looking for. Any pics on the web that you know about?  <Hmm, think I have some at home... am visiting in HI currently. The vent area gets quite clear near parturition... and the black pupils of the young are visible...> Also, she has begun to look much larger in the last 2 weeks...how soon should I separate her from her tankmates? <Sooner is better if you're going to move the fish at all... I would do so now. Bob Fenner> thanks, A.J.

Pregnant platies Dear Rob I hope that you can help me, I noticed that my platies fish tonight has become very fat and looks pregnant. How long does it take from conceiving to delivering. How will I know when she is about to deliver the babies. What precautions can I take to stop her eating her babies. She is resting on the gravel at present, so how will she act when she is about to deliver and is there anything in particular that we will notice or is there anything that we can do to keep the babies safe. I would be grateful for any information that you can give me. Regards Becky <Thank you for writing. Please take a read through the following part of our site: http://wetwebmedia.com/poeciliidfaqs.htm Others FAQs on platies, reproduction. Bob Fenner>

Fat Platy My female platy gave birth about two weeks ago but now looks pregnant again do you know what's happening? <Mmm, what do you think is happening? This fish could "just be fat"... from the types of foods you offer (any greenery, live or as food in the tank) and/or maintenance (do you do regular partial water changes?). Perhaps it is pregnant again (this happens). Do try looking for books on Livebearing Freshwater Fishes at a large library near you. Ask a librarian there to help you find what they have in the stacks or can get you on inter-library loan. You may become a breeder of new strains through your studies, involvement. Bob Fenner>

PLATY!! I have a pregnant "Mickey-mouse" platy. I know she's pregnant because she's a orange-yellow transparent color and I can see the babies inside.  <Neat> what are some signs that she is about to give BIRTH to the fry? <The vent area will become quite clear... she will "hide out" in whatever sort of "breeding grass" you're providing...> How many fry can I expect? <A few to dozens...> Thanks! -Erin of Washington P.S I heard that the color becomes darker behind the gills late in the pregnancy. Is that true? <Hmm, behind the gills? Haven't heard this before. Here's where we store the FAQs on livebearers on our site: http://wetwebmedia.com/poeciliidfaqs.htm So you can read about other peoples experiences.  Bob Fenner>

Platy repro. questions >i have two platies; one male and one female and i think that the female is pregnant how can i tell if this is true? <You will notice this female getting much more round, and the area in front of its single bottom, midline fin (the anal fin) becoming  >clearer in color... even the babies eyes will be visible close to (within days) of giving birth. Do place some "spawning grass" plant  >material or plastic equivalent for them to hide amongst. Bob Fenner> >my platy female has just given birth can you give me any info on rearing them? <A few times a day, very fine food (dried foods ground between fingers will work). Keep an eye on water quality... Are you raising with larger, parent fishes? You might want to separate them. Bob Fenner>
Re: more info about breeding pattern of mollies, especially around delivery time
hello bob, wow. this is fast. thanks. okay, I've noticed the "gravid spot" as it is called. you mentioned that this area should be "clear". yes, in my fishes, they're like "translucent", i can see the inside outline but not the shape of the babies. however in other websites, they mentioned that the gravid spot should be "dark". which is which?? <Well... depends on the "sport mutation", individual's degree of melanation in the vent area... but "does change" and one can almost always make out the young's eyes/pupils right about near parturition> what you said about not overcrowding sounds a lot like common sense. in fact, the whole day I've been thinking of getting a bigger container so at least they feel as if they have more room. <Am "full" of commonsense> you also mentioned the molly will hide among the medium (elodea in my case) to deliver her babies. some other sites mentioned the molly will settle down to the bottom and will seem lethargic, fatigued. is this also correct?? <Yes... a possibility> my one and only fry is doing well. i gave it some crushed powder from a small floating goldfish pellet. i think it only eats the powder after the powder is thoroughly soaked. but it seemed lively and healthy enough (at least not sickly). <Ah, good> I've also moved one of the females to another container as this one doesn't seem that pregnant as the others. oh yes, by balloon mollies, do you mean "pot-bellied" mollies? I've seen this term elsewhere on the web. here comes my question: how do you differentiate between a normal pot-bellied / balloon molly and a pregnant Sailfin molly?? <Very different in appearance... can be discerned easily. The pot-bellied/balloon types are REALLY round in the abdominal region> I've never seen a picture of a pot-bellied molly so I'm really hoping that my mollies are really heavy with fries and not just being the pot-bellied variety. I've written to a website on tropical fish and i was told briefly that pot-belly molly has a unusual spine curvature. to me this is very very vague indeed. if you look at a Sailfin molly, the position of the dorsal fin in the female is actually a bit to the back, more towards the caudal fin, right? <Mmm, yes> therefore, when i look at a female Sailfin molly, it looks as if she has a little bit of a "hump" back towards the caudal fin. my mollies at time stayed in one spot for quite some time, at times, they "sat" at the bottom, at times they're active, swimming up and down, up and down. is this normal behaviour?? <Yes. Do "sit" at times. Are you feeding "greens" on a daily basis?> you also mentioned that at times, a pregnant molly will reabsorb her babies, in dire circumstances? what exactly are these circumstances? <Nutritional deficiencies mostly. A lack of habitat...> i want to make sure they I'm not making their circumstances dire. since I've bought them, i want to make sure they're given good environment to live in. in place of the conventional aquarium setup (filter, etc., etc.), will a large earthenware pot about 1 1/2 feet in diameter and half a feet in height make good home for my mollies? <Maybe... would add a "sponge filter" or canister type to this container... and leave the water down a few inches or cover with a mesh (they jump)> i prefer to keep them outdoors as they seem more happy when there is sunlight. i am thinking of a such an earthenware pot with 1/4 in of gravel material at the bottom and elodea plants as needed. what I'm trying to do is to give them as much of a natural environment as possible. I've tried to read up as much as i can on this before i start. hence the initial a bit crowded home. the elodea will help to give oxygen in the daylight, provide them with cover and shade, a lotus plant will also give them cover, a 1-2 in change of water every second day to remove fish waste, use of biological pond water conditioner (those live good bacteria thing). what do you think?? do you think it would work?? <Should, but I would add the filter just the same> I've such a pond with lotus plants and a Betta and a handful of wild guppies. they seem to do very well, plant fish and all. but of course, i can't compared Betta with mollies as Betta has the ability to survive in less than desired water condition. congrats on going to Pulau Redang. how was it? <Very nice. Good accommodations there, fine people> i haven't been there, reason being i can't swim and i can't dive. i had been to Pulau Tioman but i was told that Redang is much better than Tioman and of course Pulau Perhentian, also off the Trengganu coast, beats these two islands, hands down. but if you take it from dive experts, Pulau Layang-layang is the diver's haven. <Have heard the same. Am looking forward to visiting these other island groups.> back to molly, is pot-bellied molly usually very small in size and build compared to other types of molly? <Yes, most only 2-3 cm. in length> do you have a pic of a pot-bellied molly? <Yes, but not very good. Have posted here: http://wetwebmedia.com/poeciliids.htm> would be happy if you can show it to me. my problem here is the fish shop from where i buy my fish is not that particular about proper labeling of their fish stock. they usually write it in Chinese, and i think, that is also its local name, not the standard name. for example, they called platy moonfish. i thought a moonfish looks exactly like a platy but the shopkeeper insisted it was a moonfish. i was searching and searching all over for "moonfish" when i came across a reference that said moonfish is also platy. <Yes.> hence my Sailfin molly, one with a triangular sail and one with a "rectangular" Sailfin are just referred to "mollies". i learned that the Sailfin molly with the "rectangular" dorsal fin is the Yucatan molly. but i can't remember where i read this. will appreciate any more information you can give me. thanks and regards Ashley Wong <Take a look through the wealth of information, references on these Poeciliid fishes on www.fishbase.org Bob Fenner>
Re: more info about breeding pattern of mollies, especially around delivery time
Dear bob, i want to share my good news with you. one of my mollies had given birth today and i was right there when it happened. it was around noontime. i had just changed some of the water and fed them and had just put in another handful of elodea when i noticed 1 baby fish swimming right past in front. <Neat!> right before that, i noticed that the "gravid" are of this particular molly had become very very translucent (clearish like you said) and it looked as if it might "split" apart there. soon after that, she started "spouting" out babies. at that time, there were 3 other tankmates and i quickly took them out for they started chasing after the babies. the birthing continued for well over 1 hr. it started around 12.50pm and finished around maybe 2.50pm. i think it was worth the sunburned i got today since i was able to observe firsthand the live delivery!!! :-) <Congratulations> thank you so much for your timely advice. now i am able to identify another female with a translucent gravid area (i can even see some dark shapes inside). i think maybe her time is near too. <Yes, likely> there are 16 live healthy babies, 7 eggs (!!!???) and 5 stillborn. why does the molly deliver eggs if they're not properly formed? <Perhaps miscarriages, maybe part of the development, aging of this female> was this caused by not so good conditions that i provide for them? is this normal?? <Not atypical> thanks once again. Ashley Wong <You're welcome my friend. Bob Fenner>

Livebearing Toothed Carp Questions i have two platies; one male and one female and i think that the female is pregnant how can i tell if this is true? <You will notice this female getting much more round, and the area in front of its single bottom, midline fin (the anal fin) becoming clearer in color... even the babies eyes will be visible close to (within days) of giving birth. Do place some "spawning grass" plant material or plastic equivalent for them to hide amongst. Bob Fenner>

More info about breeding pattern of mollies, especially around delivery time hi there, i came across your website while looking for material on breeding behaviour of molly. <Yikes, I've got to get more on the livebearing fishes on WWM... and soon!> two days ago i bought 5 fat, very fat female mollies and 1 Sailfin molly. I've read that fat female molly = pregnant molly = babies fry soon. <Mmm, not necessarily... some are "just fat" and there are varieties like "Balloon Mollies" that look grossly fat all the time... and an important note: it's not a good idea to move "very gravid" females... can cause real troubles. Right about the time of parturition ("birthing"?), the area called the vent (right after the anal fin below) should become clearish... so much so that you can actually see the babies eyes.> i set them up in a large fish bowl complete with some gravel and elodea plant. i noticed that mollies are happy when given elodea plant to hide around. otherwise they would be lost and panicky or even sulky. <Good point> i kept them under observation whole of day before yesterday and yesterday morning as i was hoping to catch the birthing in action and to save a few fries. i kept my fishbowl outdoor and we have tropical climate. i missed the delivery and saw one live fry and two dead (half-eaten) fries and what looked like two small round globe of "fish eggs". you know, like those fish roe featured on Japanese sushi. orange globe with a yellow center. they broke upon touch. <Yes... good observations. Do agree with your assessment> i knew then some of the mollies ate the fries. <Likely> can you give me some advice on the behavioural pattern of pregnant mollies, especially around their delivery time? this way i can tell which molly is near her delivery time, then i can move her to another "maternity ward". i can't keep watching them every single moment and i don't want fry casualty. however not one give birth today. <Hmm, well they do start hiding more right about these times... In actual practice it's better to under-crowd such fishes, provide plenty of cover as you have... allow the females to go into the media (Elodea) and release their young there... There are elaborate breeding traps and such... but as I stated above, often troubles moving females late in pregnancy> all except one female mollies have distended large abdomen. the abdomen area looked stretched. i was told that a female molly can control and delay her delivery at will. is this true? <To a certain extent, yes... and even resorb, abort the young under dire circumstances> hope you can help me. thanks Ashley Wong Malaysia <Ah, was just diving in Pulau Redang, Malaysia a couple of months back. Be chatting. Will try to write a "Mollies Article" and post on the WetWebMedia.com site for you and others soon. Bob Fenner>

Mickey mouse fish Hello, I just bought two Mickey mouse fish. I believe that one is pregnant. Being new to the fish world, I was wondering what I needed to do to take care of the baby fish. Do they lay eggs or have babies? Could you please help me. Wendy <Ah, congratulations. These fish are livebearers, like guppies if you're familiar with those (same family). You need to provide enough hiding space for some of the young to hide... Please read through the various FAQs here: http://wetwebmedia.com/poeciliidfaqs.htm re Livebearing fish care.  Bob Fenner>
Re: Mickey mouse fish
I asked you yesterday about pregnant Mickey mouse fish. I have another question. How long is the fish pregnant before she has her fry? Thanks for your help. <You would do well to read more deeply... insert the name "Platy", "Mickey Mouse Platy", "Xiphophorus maculatus" in your search engines. How long from what point? A few weeks... Bob Fenner>

Moving Near-Birthing Livebearing Freshwater Fishes Hi Bob. I just ran across your web site and have a question. We just purchased and 55 gallon tank and have Danios Platies Corydoras Guppies and one Betta.  <Keep your eye on the Betta... lest it chew on your male guppies fins> The Platy that I know to be pregnant is acting totally spastic. (meaning she is swimming up and down up and down then resting, then repeating the whole thing). I know when the guppies were going to drop they would lie on the bottom and not move a whole lot...even to eat. The platies vent is white and looks like it is dilated, and I can also see the eyes of the fry.  <Ah, good vision, observation> We just moved her to the 55 gallon and found the next morning in the 15 gallon a baby that was hers BUT VERY SMALL. I took this as a premature. But she hasn't dropped anymore. Any help would be wonderful...Thanks <Hmm, could be this is "all there is"... Maybe the others were stillborn, or more likely consumed... I would place some live "grass" like plant material or artificial breeding medium going forward, and/or try moving the pregnant female to another system well in advance of parturition. Bob Fenner> Cheri
Re: Moving Near-Birthing Livebearing Freshwater Fishes
Thanks for the fast response! I know I had a guppy that appeared to be miscarrying (SP) then finally died...poor thing. I'll keep an eye on her. I want to get some java moss to put in the tank...the plastic stuff that I have seems to rigid. Again thanks! Cheri <Agreed all the way around. Please take a look through the "Plant Index" part of the site: www.WetWebMedia.com for ideas on good "baby hiding plants" like Anacharis/Elodea, Myriophyllum/Milfoil, and Ceratophyllum/Coontail or Hornwort. Bob Fenner>

Questions about my guppy fry Mr. Robert Fenner, My female guppy has given birth to twelve fry. I had checked a lot of websites and all the web sites said that i could feed the fry with egg yolk. Is it true that the fry could eat the egg yolk? <Hmm, actually the cooked egg yolk is not such a good idea... low acceptability as you know, too easily sinks and pollutes water... I would try either grinding some thin flake food between your fingers or in a mortar/pestle or just buy a dried "fry" food (Tetra makes one for livebearers like guppies, and egg-layers). There are liquid food preparations as well, but I would stick with a dried one. Do feed as often as you can (several times daily ideally) very small amounts (should be mostly consumed, little falling to the bottom. Also, do place some live plant material here... a type of bunch plant. Please read on our site: http://wetwebmedia.com/plttks.htm> If i were to feed them with a piece of flake without tearing it to small pieces, will the fly be able to eat it? And every time I put food into the tank for them, they don't seems to eat the food. Why? <Not familiar, palatable> Hope that you will e-mail me the answers. Thank you for your help. <<Be chatting my friend. Bob Fenner>

Swordtail Pregnant? Hi. I HAD 2 pineapple swordtails. One female and a male. The male died, but I think my female may be pregnant. It is quite large in size and has a darker area behind her stomached. In the dark area are small black dots. <Ah... likely the eyes/pupils of soon to be baby swordtails> I was wondering if this is the area where you see the babies or if was more near the head. Its been this way for about 3 days now. My temp. in my tank is 77. Should it be warmer? How long will it take so I know when to look for the babies? Thanks. <Do provide some sort of "breeding grass" (real or artificial), leave the temperature where it is, and read here re others experiences with livebearers: http://www.wetwebmedia.com/poeciliidfaqs.htm and the article, link before. Bob Fenner>

Question about mollies Hi, My balloon molly gave birth to about 30 babies a week and 4 days ago. Every day 3 or 4 die. There are only 3 babies left now. I had the aquarium water tested by a local pet store and they said the pH, ammonia, etc. was all fine. I keep the water temperature around 76-78. The babies are in a breeding net with fake plants, and I feed them several times a day finely crushed up flake food. Do you know why they are dying or what I could do to keep the remaining 3 alive? Thank you Rebecca <Is this the first "batch" your mollies have had? If so, the first few groups of young sometimes do poorly. Also, take care not to move your female mollies too close to giving birth. Please read over others experiences with these mollies, posted here: http://www.wetwebmedia.com/poeciliidfaqs.htm Bob Fenner>

Those crazy Mollies! Dear Bob (or fellow expert), <fellow expert Anthony in your service> My gosh, I don't know what to do with all these babies! About 5 weeks ago my 'test fish' mollies gave birth to 12 babies. They are growing and look very healthy, but now that fish has had more babies, and I think there are about 17 new fry.  <Did you know that some young livebearer's can reproduce at 8 weeks old!!! Perhaps we should find a recipe for mollies... hehe> My tank is 39 gallons, and set up as brackish. The pet store said they would take the older ones, but wanted me to let them get a little bigger so they can sell them. I read that overcrowding can cause the Sailfins not to fully develop, <true of most/all fish> and I think that is one of the most attractive traits of this fish.  <with many fishes this can be partially compensated for by frequent (weekly or more often) water changes> How long do you think it will take for these to get a little bigger, <hard to say... roughly 6-12 weeks with good feeding and frequent water changes> and now with these new fish is overcrowding an issue yet?  <so very much so> I sure would love to add other species to the tank, but I feel kind of trapped, even though I love the mollies. I wish there were a birth control pill I could just drop in the tank!  <perhaps be content with just a male Sailfin> LOL Your response is always greatly appreciated. I know you must be very busy. Sue <with kind regards, Anthony>
Re: Those crazy Mollies!
Thank you Anthony! Your response is GREATLY appreciated!  <you are very welcome> I will take your advice, and do weekly water changes. I love this hobby, I think you all do a great service to those of us who are just as excited and motivated...I hope you're getting paid! (somehow) <in many different and wonderful ways> ...yeah, does Mollie-lemon-garlic-almandine sound good to you? LOL (with rice, of course) <I prefer "freshwater" mollies... I'm watching my sodium intake...hehe> {sick} just joking.. Thanks again! Sue <best regards, Anthony>

Livebearing fish babies How are you? <Cheers, my friend> I am Nader Afshar .I am engineer from Iran, I have many guppy and platy and molly , but I have a problem, my fishes [have babies] every month ,guppy and platy kids are live but the kids of mollies are sick and dead many of them every day ,why? <is there enough salt in the parent's tank? 1.004 on a hydrometer?> I give them (salt ,antibiotic tetracycline, Gentamycin, moldy vitamins ,and fresh water and Methylene blue ), <the Methylene blue can be very harsh on the babies. Reduce or eliminate it temporarily to see if that doesn't improve survival. Leave all else the same> I do any work and test very ways but I cannot take positive result , what can I do ?Is there any drug for this sick? please help me ,thank you very much, bye <with kind regards, Anthony>

Balloon Molly Fry I managed to save one fry from a batch of balloon mollies. Is it supposed to look totally different from its mother and father, both silver balloon mollies? It looks black and very thin. Thanks. -James Kim <This is a normal appearance. The young change as they grow, it will likely develop a into darker, more balloon-shape. Bob Fenner>

Feeder guppies (culture) Hi Mr. Fenner: I would like to raise my own feeder guppies for my cichlids. Could you give me any advice on this topic? Thinking about setting up just a 10 gal tank, but not sure about water parameters and such. Any help would be appreciated. Thanks in advance. <Let's see... a bigger tank would be better for production, maintenance... Frequent partial water changes (twenty percent or so weekly, while gravel vacuuming the tank... Lots of frequent, small feedings with nutritious foods (a timer with a dried-food hopper automatically sprinkling a bit ten or more times a day is a good idea). Some real filamentous plants or artificial "breeding grass" (wouldn't use breeding "traps" here, too much trouble) to add habitat, save more of the young from adult predation... Maybe making sure the water is a bit hard and alkaline, even adding a teaspoon of salt per water change... Harvesting conscientiously (always leaving a few larger breeding size females, one or two males of size). This is about "it". Bob Fenner> Sincerely Shirley

Breeding Balloon Mollies, Questions Dear Robert, <<Not Robert, JasonC filling in while Bob is out diving.>> I currently have two female balloon mollies, one pure white the other marble colored, a male balloon molly which is orange and black, and an algae eater in my 5.5 gallon tank. All the fish are doing well, the pH, nitrite, and ammonia levels are all at the appropriate levels, and the tank is at a constant 75 degrees F, but it seems that the females are not willing to mate with the male. Is this normal behavior for balloon mollies? Could there be an explanation for this reluctance? Thanks. -James Kim <<James, I'm going to take a quick guess but also forward your email to a friend who knows much more about freshwater fish than I do. My guess, and Lorenzo will tell us both if I am wrong, is that 5.5g is a little small for breeding, and the pair [if they truly want to be a pair] doesn't feel they've found the right place to brood. Cheers, J -- >>

Dying baby guppies My baby guppies get pointed tails and die at about 1 month of age. I've cleaned my tank and started over many times. This continues to happen... I've been told this is caused by a high ammonia level in the tank... but it tests out at 0... no ammonia. Sometimes the babies turn dark in color a day or two before they die. Any idea what this is, why it happens and how to fix it? I have 3 month old baby swords in the same tank that are never affected by this. They remain alive and healthy. <hmmm.... not a clear symptom but many possibilities. Do consider the diet for starters... enough protein hopefully? Little or no brine shrimp hopefully? Are there any other symptoms on the body or with behavior (rapid gilling, clamped fins)? Do examine the disease section here on WWM or read through Dieter Untergasser's Handbook of Fish Diseases. Best regards, Anthony>

Pregnant swordtail? I have a female swordtail that has grown bigger over the last few weeks. I used to have a male and I saw them mating but he ended up dying. I've looked around and found out about a "gravid spot,"  <very good!> or dark triangle, above the anal fin which indicates that the fish is pregnant. I see this dark triangle, but does it really mean that the fish is pregnant? <yes... only a gravid female would have it. Swords do breed easily and many livebearers store sperm and can have several broods more without another coupling with a male. Best regards, Anthony>

Who wrote this, and is this a livebearer question, or an oviparous question? Livebearers gestation 7/10/03  Thanks for the response.  how long is the duration period for a female to keep her egg sack, and what's the time for the eggs being dropped, fertilized and we get some babies?? <mollies are somewhat longer than other livebearers (matter of weeks, month plus) depending on water temperature. Goldfish fry will be apparent in less than two weeks... again depending on water temp.> 

Livebearing Fish How do I tell when a female molly is pregnant and how do I know when it will give birth <do look over these enclosed links http://www.wetwebmedia.com/FWSubWebIndex/livebearers.htm http://www.wetwebmedia.com/FWSubWebIndex/poeciliids.htm http://www.wetwebmedia.com/FWSubWebIndex/mollyfaqs.htm  faq's read through the ones pertaining to birth, good luck with your livebearers, IanB>

Platy Breeding <Hello.> I have a platy question.  Is it a big deal if platies inbreed and if it is a big deal could it have health risks?  I haven't had to face that problem yet with my platies but I was just wondering for the future.   <Well, any inbreeding is a concern to some extent, but livebearers especially are extremely inbred for color, fin shape, etc.  The most important thing is that you avoid breeding fish with obvious undesirable genetic deformities, and be sure to cull the brood - 'weed out' any misshapen/deformed young.  These culls can be used as food for larger fish.  -Sabrina>

Platies I recently bought a few platies and I was wondering how u tell the difference between the male and females. <normally the males are more colorful and have larger more attractive fins. the females are more drab in their coloration and have short fins. IanB> thanks <<Mmm, and as livebearing toothed carps with internal fertilization, the males have modified anal fins (the one underneath their bodies, behind the "belly"). On males these are tube-shaped and on females they're fan-shaped in profile. RMF>>

Sexing swordtail fry, molly issues (10/11/03) <Hi! Ananda here tonight...> Hi guys, your website has been most resourceful to me in my several months of fishkeeping. <Good to hear!> I set up my fish tank about four months ago and one of my 'starter' swordtails dropped about 10 babies. Since the tank was still cycling, most of the babies died, but one tough little thing is still with us. It's about one inch long and doesn't show any signs of being male (no sword, no gonopodium) but since it is the only survivor I'm not sure if it would have developed those yet or not. It's about 3 months old. Is it safe to assume it's a female? <Not yet...some livebearers mature more quickly than others, even within the same brood.> Along the same lines, I just had a drop of 11 Mollies in the last 2 weeks, they are growing rapidly!  However, I have had 3 deaths so far, and I was baffled as to why.  They all seemed to eat well (they are black so I can't see if their bellies are full as easily as the sword, but they produce little 'threads' on a regular basis) and their water quality is excellent (no nitrates/trites or ammonia, neutral PH, temp about 80).   <Neutral pH is actually a little low for mollies; they prefer more alkaline systems.> The only things I could think of is that they were in a too brightly lit tank (I have a triple-tube light in my main tank and the breeder net limits them to the surface, right underneath it) or that they were in a completely freshwater environment, so I coaxed them all into a jar and transferred them to the isolation tank their mother is currently in (my red-tailed shark chases her around something awful, maybe he thinks she's another shark?  I heard they were territorial with others of their species, but they leave all the other fish alone)   <My guess is that the red-tail has staked out the entire bottom of the tank as its territory, and is getting after the molly for intruding...> Anyways, I have the isolation tank set up as brackish to help her recover from the stress of being shark-harassed and giving birth.   <Good idea.> I slowly acclimated the babies to the water, since I figured transferring them from fresh to brackish rapidly would be hard on them. <It can be, in part because the marine salt usually used for brackish tanks also raises the pH.> Now they are in a breeder net in a brackish tank with some floaty Hygrophila for shade (the light in the iso tank is dimmer anyway).  No deaths in 3 days!  Have I fixed the problem, or is there another environmental factor at fault? <Mollies often do better in brackish water. Failing that, they should be kept in a system with a pH above 7.2.> Also, when will their gender characteristics show up? <That totally depends on the individual. Even in the same brood, I've had some show male characteristics at only about three months old, while some waited six and seven months. Some take even longer. From birth, the majority of the molly's energy is devoted to growth. At some point, that changes, and the gender characteristics develop. The longer the gender development is delayed, the longer the molly will grow as a juvenile, and the bigger the adult fish. The biggest molly I ever had was one I bought as a "female", when it was probably about 6-8 months old. It started developing a Sailfin and gonopodium several months later. He got to be over 4" long (plus tail).> Thanks for tolerating my rambling, <No problem! I'll happily ramble on about mollies anytime...> Andrea <Best of luck with the fry... --Ananda>

Guppy and platy fry I recently bought a 50 gallon tank with guppies and red wag platies and I have babies every where and I don't know how to tell the difference in the fry . Some are grey and some are gold . please help me! I have a lot of experience with Guppies but none with Platies. I would greatly appreciate your advice .   Thanks a lot Kennie >>Dear Kennie; You will have to wait until the fry grow out and get big enough for you to see what species they are. How long have you had the platies? The females can give birth to different colored babies, depending on what the father looked like. Also, livebearers like platies can "hold" sperm from past males, for example, males in the same tank at the LFS, then the females will give birth later on. I hope you will have a colorful collection of new babies to brighten up your tank! You can help the babies by adding some plants, like java fern or duckweed to your tank, this will give the babies a place to hide from the adults until they get bigger. Livebearers are pretty good at eating their own young. Make sure you do regular, partial water changes to keep your fish in good health. Good luck! -Gwen<<                       

Freshwater breeding Hi, this is a great site its really help me a lot. I am fairly new to aquariums (besides Bettas in 1 1/2 gal. bowls) and I have been through a lot of stuff in my first more or less six months. But now I think I've got a pretty good understanding of things and my tank has been doing great. And eventually I would like to try and start breeding fish, could you recommend any fish that don't require a lot of space (10 gal. at most) are easy to breed, and easy to raise the fry? I know it sounds kind of specific but I want to start out as slow as possible to avoid any more fish disasters. < Look at small live bearers such as guppies and platies. They give birth to live fry and you won't have to worry about eggs hatching. Just keep lots of floating plants in the tank for the babies to hide in. They will eat the same food as the adults you just have to break it up into smaller pieces. Keep the adults well fed are they will eat their babies.-Chuck> Thanks a lot, Mike

Livebearer sex change I placed five grown females into a community tank, > and a month later have four females and a male?  Do they morph if no males are available? > <Hee hee... females, males of what?   swordtails <Actually, yes.... this and other livebearing toothed carps (Poeciliids) can/do change their sex in events of disproportionality, need. Bob Fenner>

Fish that had babies in the tank and got sucked up by the filter Hello, and Thanks. <Hi and you are welcome.  This is Jorie.> We are new to fish and everything that goes into it. One of the fish gave birth to some baby fish and I have seen about 7 Tadpoles in the filter. My question is do I take the filter out and clean the Dead fish off or do I leave them there until I get ready to clean the tank out in about a week or two. <First off, I think you probably are speaking of livebearer fry, not tadpoles (unless you have frogs in the tank!).  You absolutely should remove any and all dead fish, including babies, ASAP, as their decay will pollute the water and cause spikes in ammonia, nitrite and/or nitrate.  Remove the carcasses, clean the filter, and do a large water change.  Are you familiar with the cycling process of the fish tank? I would suggest a book by the name of "The Simple Guide to Freshwater Aquariums" by David E. Boruchowitz as an excellent beginning point...will explaining much that is essential to keeping your new fish happy and healthy.  In general, depending on the size of you tank and how heavily stocked it is, you will want to do water changes *at least* once per week, possibly more while the initial phase of cycling is going on (since you've got fish in there already).  I suggest you purchase a water test kit that includes ammonia, nitrite and nitrate tests, as well as pH...the first three are toxins incredibly harmful, even fatal, to fish, and if you are measuring any amounts of any of the three elements at all, you need to do a water change ASAP.> Thank You for your help. Mr. Poje <Hope I helped.  Do check out that book and feel free to ask any follow up questions you may have. Jorie>

Don's shortest answer ever I have a tank with swordtails and platy's and I was wondering if different species of swordtails could breed with other swordtails and the same for the platy's. Also, can the platy's and swordtails cross breed? <Yes, yes and yes> Clint <Don>

My pregnant swordtail Hi bob <Don here today> could you tell me how long it takes a female to give birth once she becomes pregnant? thanks Most live bearers will drop fry every three to six weeks.

My fishes, mainly livebearer questions Hello Crew,          I just want to say that I think you guys r the best. And I have a few questions to ask. I have a 20 gallon tank with 9 fish in it. 4 of the fish are swordtails. I have 1 female red swordtail, 1 female pineapple swordtail, and 2 male pineapple swordtails. I just bought them last week and the female pineapple swordtail is pregnant. We don't know how long she has been pregnant so we put her in a breeder just in case she is supposed to have them any day. Will she eat the babies as she has them and should I be feeding her a little bit more than I usually do because she is pregnant? <She may eat some of the young... a good idea to provide a bit of real or faux "spawning grass" for the young to hide in>          I have another question. In a one gallon tank I have 2 baby mollies. We got them at a pet store on accident. In the tank I have about an inch of gravel, a baby hide out, 1 small plant and an under gravel filter. I am also doing water changes every 2 days that I take out about 1/2 of a jam jar and replace it with fresh water. <Good technique> I am feeding them powdered tropical fish flakes and dried baby brine shrimp. Is that an O.K. place 4 them. Of course I am going to put them in the 20 gallon tank when they r big enough. <Sounds good>         Oh ya and when the swordtail has her babies will the baby mollies eat the swordtail babies. <All should get along fine... as long as they're about the same size> Thanks again 4 all of your help.                                              Kelsey Meadows Age 12  La Quinta C.A <Welcome. Bob Fenner>

Link between platy fry gender and temperature? Hi, <Hello there> An acquaintance of mine recently mentioned a link between aquarium temperature and the gender of platies - he believes that his fry ended up all male because he'd kept his tank too warm.   <Yes, probable... one speculation is the link here and the demise of dinosaurs...> I haven't been able to find any references on this topic and was wondering if you could shed some light:  have you heard of this phenomenon, and if so, what temperature ranges are we talking about? Thanks, Joy <Get thee to a large library! Please see here: http://www.wetwebmedia.com/litsrchart.htm Bob Fenner>

Molly and Guppy?!?  9/3/05 Hi my name is Michelle and I have a 2.5 gallon tank with three albino Corys, three white cloud fish (2 males and 1 fat female), one female silver molly and one male blue guppy who is absolutely gorgeous.  All of my fish get along just great and love each other even with the some what cramped space.  I got the albino Corys about 6 months ago, the white cloud fish 4 years ago, the male guppy 6 months ago and the silver molly 9 months ago.  Getting to the point though I have a problem and was wondering if you could give me a few answers.  About 5 weeks ago I woke up and was about to feed my fish when I noticed little tiny black slivers of fish darting in and out of a java plant I have in my tank.  There were probably about 10 of them in all.  When I realized that they were baby fish I grabbed my net and managed to save four of them before my catfish got them.  I put the baby fry into a 2 gallon tank my mating Bettas had been using and as the four fry grew I learned that they had definitely come from my silver molly because they all look just like her now only smaller.  I thought it was some kind of asexual fish fluke thing at first because she is the only silver molly in my tank and I had no other way to explain it.  But now, 5 weeks from that incident, tonight I went to feed my fish again for the night and I noticed the same little black fry in my java plant and saved 4 of the little guys again and they look just like the first batch of fry from 5 weeks ago.  I looked on some websites and they all pretty much say live bearers need at least one male and one female to make babies.  I know some females come from pet stores pregnant but I bought her back in early December 2004 and she is just now all of a sudden having babies...WHY?...HOW? <Mmm, some livebearers, including molly species, are capable of storing sperm in their reproductive tracts, using it later> Is there some way the molly and guppy could be mating? <No... though some crosses do happen (platies and swordtails for instance)> The male guppy follows her around the tank every where and he isn't aggressive and never nips or hurts her or other fish he is just very determined to be with her and only her...does that mean they could be mates or something even though they are totally different breeds of fish?  I know I sound stupid but I am so confused and never wanted the babies which is why I only got the one guppy and one molly to begin with since Pet Co told me they breed live young often when in pairs.  How can I make her stop having babies every 5 weeks? <This will happen over time> Where can I get rid of these poor little babies? <Perhaps give them to friends if their parents, guardians agree... trade into your fish store for credit...> I feel bad but I no tank room for 8 new silver mollies.  PLEASE HELP ME!!! Michelle <Thank you for writing. Bob Fenner>

Re: baby livebearers in a net... learning, making up your own mind  9/9/05 I was told by PetSmart employees to leave the babies in the breeding net from birth until they are 6 months old. <Uh, no... only should be there until grown past the point of being consumed...>   They are in a breeding net that is in a 10 gallon tank.  This aquarium was given to me about 5 months ago with fish in it & no filter.  Everything that I have done since was on the advice of PetSmart employees. <So? What do you think? Think for yourself> I immediately bought a power filter and have done weekly 10% water changes ( I use bottled spring water ). <Not generally necessary, recommended> The babies were born about two weeks after I got the tank and seemed to be doing well until now.  I was told I would be "lucky" if any survived. <Why... lucky?>   I went to Pet Supermarket this morning and had the water tested.  The pH was "perfect" and there was no ammonia. <Mmm, know that ammonia is transient... can, does leave solution... enroute>   I bought aquarium salt and stress coat ( advice given by the employee ) and used both in the tank this morning.  I was told not to give them any more penicillin.  I feed them twice a day with crushed tropical fish flakes ( of course, they aren't eating for the last four days ).  Unfortunately, everyone I talk to has a different suggestion on how to care for these fish.  I want to do the best thing for these babies and any advice you have would be appreciated! <... please read... on WWM, books... and make up your own mind. My/our opinions, experiences are archived here/there. Bob Fenner>   

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