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FAQs on the Swordtail Reproduction

Related Articles: Swordtails & Poeciliids: Guppies, Platies, Swordtails, Mollies by Neale Monks, Livebearing Fishes by Bob Fenner,

Related FAQs: Swordtails 1, Swordtails 2, Swordtail Identification, Swordtail Behavior, Swordtail Compatibility, Swordtail Selection, Swordtail Systems, Swordtail Feeding, Swordtail Disease, Livebearers, Guppies, Platies, Mollies,

How to tell if my neon swordtail is pregnant Pregnant livebearers usually are swollen and have a darkened area near the ventral region. These are the eyes of the fry.-Chuck>

Pregnant swordtail      1/8/14
I had a pregnant swordtail and I talked to my local pet store and they suggested to put her in a breeding box. I put her in there a couple of days ago and when I checked on her this morning she didn't look pregnant any more. The black spot was gone and her belly was considerably smaller. There were no babies in the bottom of the breeding box and no sign that she had given birth. There weren't any egg sacs or anything. She was very agitated and I feared that she would not survive if I kept her in there. I let her out and now she seems fine. Is it possible that the babies died in utero?
<Some possibility, yes>
Wouldn't she still give birth to the still born babies?
<Not necessarily; does happen; but might have been resorbed>
Thank you for any help and advice you can offer me. I feel horrible if putting her in that box stressed her out.
<I am not a fan of moving "late gestation" Swords (or Mollies...); to the small "breeding" devices sold in the trade. As you hint; there is too much stress involved. Better to leave the female/s in place and hope that some young will survive (provide "spawning" grass/es and/or such) or move the female/s to another (planted) system for delivering their young... days in advance. Bob Fenner>
Re: Pregnant swordtail      1/8/14

Thank for your quick response. I only have a 10 gallon tank will the spawning grass be too much for my tank size? ~Jennifer
<Mmm; no... a bunch (see WWM re) will be fine of a few species, or phony/plastic... gone over on the site. BobF; who does realize this system is too small for Xiphophorus>

Two Day Old Fry Flashing - 1/25/13
Dear WWM Crew,
<Hi Stephanie, Rick here>
I have been reading as many pages as I've found on your amazing website, but unfortunately couldn't find a definite answer to my question. It is surely there, but I may have missed it. I bought 2 male swordtails about a year ago and kept them in a 10gl. tank. About 5 months ago I set up a 55gl. freshwater tank for my red tailed shark and to put the male swordtails in.
I did this, and decided to get the males some female companions. I bought 6 fat healthy looking females', acclimated them and all went well.
<No quarantine period, I'm guessing, since you said you no longer have the 10 gallon tank.>
After a lot of starring and researching, I noticed a few of the females appeared pregnant, which really did not surprise me at all.
<Happens a lot with livebearers.>
So I've been waiting anxiously for the birthing. I had to get rid of my 10gl, it was my ex's and even though he doesn't want to use the tank, he wanted it back so I don't have anything to put the fry in.
<Might want to pick one up. They're useful to have on hand.>
I figured I would deal with that issue once I saw fry swimming around. Yesterday morning, around 10am I went to my room and as I usually do, checked on my fish. I then noticed 8 tiny little fry swimming around at the top of the tank in one corner near the heater. I was extremely excited and immediately knew they needed a better hiding spot, so I yanked up a couple of the fake plants I have in there and made a little haven for them in the corner and blocked it off using my glass scrapers so only the fry can get back in there. Today I noticed the female who had given birth is not eating and she flashed a few times against the live sword plant.
<Probably brought whatever it is into the tank with her. Thus, the suggested quarantine period.>
 Then as I watched the fry very closely, I saw two of them "flashing" against the leaves of the fake plants I used to help hide them!
<Probably got it from Mom.>
The only fish that are in the tank are 2 Male Swordtail's, 6 Females, 1 Medium size Red Tailed Shark, 1 Pleco and 10 medium size Apple Snails. I do water changes every weekend and check my parameters regularly and they are:
Ammonia 0 Nitrite & Nitrate 0 and PH 8.2, Temperature stays at 72°F. I had read on your site that Ich has several life stages and that it's very possible for your fish to be in the beginning stages of infestation and them not be showing the notorious 'white spots'. I have turned my heater up and will be adding another small heater to help boost the temperature up to 85°F, gradually. My LFS owner said to buy fresh garlic and cut very very thin slices and put it in during evening feeding, saying that fish with Ich will search out the garlic. Is it possible that my fish have ich and through birthing gave it to the fry? If so will the fry survive the ich?
I've never had ich before in my 3yrs. of working with Saltwater & Freshwater tanks so I am a bit naive. I really don't want to use any copper treatments because I am afraid as delicate as fry are, it would severely injure or kill them. Any advice and help is greatly appreciated guys.
Thanks so much!
<First, you don't know for sure that you have ich. You have flashing, and they do that when their skin is itchy. Could be ich, could be something else.
I would seriously consider getting a 10-gallon tank, and maybe a 2-1/2 gallon tank also, so you can isolate
the affected fish and keep the fry separate from the adults.  Used tanks from Goodwill would be fine for this as long as you can keep them warm enough and aerated.   I urge you to do this because treating your entire display tank is excessive, exposes the healthy residents to meds unnecessarily, and gets expensive since you have to treat all the water.
Look for other symptoms like ich spots (the prime suspect), but also slimy or cloudy skin, red areas on the skin, and so on.  Occasional flashing is normal, I mean, you get itchy sometimes too, but frequent flashing does mean something is wrong.  Better to try to identify what than to start shotgunning meds blindly.  You can read through this article by Bob Fenner for some general disease clues: http://www.wetwebmedia.com/FWSubWebIndex/SolnChartFWDisArt.htm
Here's the article on freshwater ich: http://www.wetwebmedia.com/FWSubWebIndex/fwich.htm
Some FAQs on Ich mostly answered by Neale:: http://www.wetwebmedia.com/FWSubWebIndex/fwichcausdiag.htm >
Stephanie L.
<Hope it helps. - Rick>

Lyretail swordtail breeding   12/31/12
I have a question on breeding lyretail swordtails. I know that you have to mate a lyretail female with a NORMAL FINNED male to get an approximate ratio of 50% normal and 50% lyretails. I have bought several lyretail females from my LFS and they all looked fertile based on body shape (fat looking, and the clearly visible eggs through the gravid spot on lighter varieties, etc). I know that fertility in Xiphophorus is not always guaranteed as most if not all swordtails and platys have genes of 1 or more specie in its heritage along the way, so not all females are guaranteed fertile and not all males are guaranteed fertile. I chose my breeders carefully based on fat looking females with clearly visible eggs thru the gravid spot
<Not reliable with fish as large as Swordtails; only really reliable on small livebearers, Guppy-sized and less.>
particularly on the lighter colored varieties, and with males i look for ones that are actively courting females. Now onto my question. Every lyretailed female I've tried mating to normal finned males never worked.
<I see.>
The males never even tried mating with them all the years i have tried.
<That is very odd. Are you keeping them correctly? Large tank, swimming space, floating plants, cool water, lots of oxygen, a diet rich in greens?>
So should i just get a separate aquarium and put in a normal finned male and a lyretailed female by itself and wait for the female to get pregnant then separate her?
<Livebearers tend to be more settled and breed more readily in groups. Try 2-3 males, 4-6 females per tank.>
I never realized how hard it is breeding lyretail swordtails even though they are the SAME specie and by using the recommended normal finned male to lyretailed female method still doesn't work for me. There has to be something I'm not doing right preventing me success in having a female lyretail swordtail get pregnant?
<What you're reporting is very unusual. Why not try with plain vanilla Swordtails, ideally, a wild-type like Green Swordtails? Even better would be a pure-bred form, like Xiphophorus alvarezi, a species periodically seen in good aquarium shops. See if you can get them to breed. If you can, then you are probably doing the right thing. Then graduate to the fancy varieties. Consider joining the American Livebearer Association or at least their forum, here:
While I've heard mixed reports on how welcoming these guys are, they surely know their stuff when it comes to livebearers. The livebearers I personally breed from time to time are the Halfbeaks, and what applies to them may not necessarily apply to your Swordtails. But with Halfbeaks, water chemistry and quality are as important as ever, but the age of the fish and the quality of their diet to seem to be central to successful breeding. Cheers, Neale.>

Male swordtail not interested in mating     12/24/12
Hi, i have 2 female swordtails-a red wag and a white lyretail. Now i had a normal finned white male, he chose the red wag as his favourite. Always bugging her, swimming near her, trying to mate 24/7.
<What they do. Keep at least two females per male for best results.>
He still mated with they white lyre female too. Now i got rid of him to the lfs because i wanted to change colors in males. I bought a marigold male. He is deeper bodied then my white male i had, and his sword is shorter. Now i got the marigold swordtail male 2 weeks ago. He is healthy, but he is not interested one bit in the 2 females, just eats like a pig and does his own thing by himself.
<Fair enough. Lucky females!>
Do you think he may be sterile?
<Unlikely, but in any event fertility won't be connected with his sex drive any more than it is with humans.>
I was wondering if body shape of male swordtails may indicate sterility in their genus (my white male was long, slender, long sword..he mated any chance he got. this marigold male is deeper bodied then him, his sword is also shorter and he doesn't mate or even seem interested to....so i was just curious).
<Not heard of this association between shape and fertility. On the whole Swordtails are robust, hearty fish if given the right conditions (cool water, lots of water current and oxygen, hard and alkaline water chemistry, and a diet rich in greens). Under the wrong conditions as with any fish their fertility may drop, with fatty diets in particular being associated with poor breeding potential.>
Since its been 2 weeks now that i had him, and he is still not even trying or even interested in the females, should i just go back to my lfs and pick out a new male and try him??. Whats ur view on why he may be doing this?.
(Not being interested in the females), and should i exchange him for a new male and try again?. Thanks
<If you want pet fish, then this is the ideal male. He isn't harassing the females, so they'll be much happier. If you want to breed Swordtails, then randomly mixing varieties isn't the thing to do anyway (the mongrel fry won't be worth much, if anything, to your local retailer). Write back if you want tips on how to breed Swordtails. Cheers, Neale.>
Re: Male swordtail not interested in mating-would like swordtail mating tips    12/24/12

I would like some tips on breeding swordtails.
I have read everywhere on almost every website on swordtails they suggest to have the water temperatures either 68-82f, some say 75-80f, some say 71-78f, and some say keep them at a minimum of 78f, to a maximum of 82 f, as the warmer the water the more active they are and the more diet they have.
<Hmm… no. Swordtails in the wild surely are exposed to quite a wide range of temperatures, and the farmed (hybrid) varieties sold in aquarium shops are pretty adaptable. But the warmer they are, the faster they grow and the more oxygen they need to do well (warm water contains less oxygen, so filtration and stocking levels become more difficult to manage at higher temperatures). The bottom line is that Swordtails and Platies are both best kept at 22-25 C/72-77 F; you'll find numbers similar to these in just about every decent aquarium book. Note that this is towards the cool end of what we regard as "tropical" temperature, and ideal for lots of other low-end tropical species: Neons, Corydoras and Danios to name but three.>
I am confused as to what to believe in regards to water temperature and swordtails. What other tips can you offer me on the proper breeding of swordtails?
<Lots of floating plants! Swordtails are notorious cannibals, and more often than not when people don't find Swordtail fry, it's not because their females weren't pregnant but because the fry were eaten within hours of being born. That said, miscarriages are common in livebearers where females are bullied by males, and again, floating plants help here, providing shelter for the females. Also keep more females than males, at least 2 females per 1 male, but ideally even more than that.>
I have a spare tank and i am also wanting to hybridize x. maculatus with x. helleri. (I am aware that every swordtail in a petshop is already a hybrid to some degree as generations ago they were crossed with platys to create those varieties we enjoy. Its just I've always liked the appearance of the f1 hybrids in regards to their neat random colors and the short, weird looking swords on some of the male f1s).
<Do also look out for the outstanding Xiphophorus xiphidium, the true "Swordtail Platy".>
So my question is what setup should i use to achieve success-male sword to 2 or 3 female maculatus platies or male maculatus platy to 2 or 3 female swords?
<Ah now, there are some differences between Platies and Swordtails that can make housing them together slightly less easy than you'd expect. Swordtails prefer running water, whereas Platies prefer still water. Swordtails are also substantially more aggressive. In real terms this isn't a killer, because the two species coexist quite well in large tanks with some running water and some stiller areas. But do be aware of these differences and plan accordingly.>
Im mentioning x. maculatus because I read that it is much easier to use x. maculatus in hybridization then it is to use x. variatus as x. helleri is more closely related to x. maculatus then x. helleri.
<Xiphophorus variatus, the subtropical Variatus Platy, is a lovely fish, but you may well be right that it is less frequently hybridised than X. helleri and X. maculatus. If nothing else, the fact Xiphophorus variatus prefers cooler conditions may count against it (it actually does rather well at room temperature).>
And my other aquarium I have I want to breed lyretail swordtails. I am aware you have to use a normal finned male to a lyretailed female and that way 50% of the young will be lyretails. Can any color variety of male swordtail mate any color of lyretail females?
<Mate, yes; but will the offspring be viable, I do not know. Are you aware of the American Livebearer Association and other clubs such as these? You may find them particularly helpful.>
(I am only asking this because I've had lyretail females in the past and no normal finned male swordtails have ever mated with any lyretail female swordtails I've had. I don't know if maybe the males thought they were a different species or not lol). I have 4 fish tanks so I would like your advice on all of this and any other tips you can offer me.
<What else…? Hmm… do remember to feed plant-based foods as well as the usual flake; provide regular water changes (nitrate is a real "mood killer" for many fish species); and be aware of possible spawning triggers like (cool) water changes, use of live foods, sunshine in the morning. These spawning triggers matter more for egg-layers, but they won't harm livebearers, and may provide a useful nudge for reticent males. All this said, breeding is so likely with Xiphophorus spp. that the main reason for failure will them will be cannibalism of the fry.>
Also let me know your information/knowledge on how to hybridize X. helleri with x. maculatus successfully. thank you
<Welcome, Neale.>

Xiphophorus hybridization   11/15/12
hi i have a few questions, i want to hybridize platys with swordtails.
<Farmed Platies and Swordtails are hybrids already…>
i know there already hybrids to begin with but i want to breed these together anyways to make my own unique hybrids.
<I see.>
i read that a male X. variatus will inseminate x helleri females but a male helleri wont typically inseminate x variatus females.
<Not sure that's true. Indeed, I'm fairly sure it's false.>
now, i have male black Redtail variatus platies and 2 female Redwag swordtails. now what setup would you recommend?
<Both are low-end tropicals that need hard, alkaline water; 22-25 degrees C, 10+ degrees dH. Otherwise, the key difference is Platies prefer slow water current while Swordtails do best with a moderate current. Both are of course algae-eaters more than anything else.>
(1male variatus to 1 female swordtail) or 2 male variatus to 1 or 2 female swordtails?
<More males than females.>
and what size tank should i use to get them to breed together?
<Platies 20+ gallons, Swordtails 30+ gallons. This reflects their different sizes and the fact Swordtails are much faster swimmers and more active. Plus, male Swordtails tend to be substantially more aggressive than male Platies.>
i want to create my own variety of Mickey mouse swordtails by using Mickey mouse x. maculatus to female swordtails. but i read everywhere that swordtails and platies hybridize "freely" yet every time I've tried to mate x. maculatus to x. helleri they never mate they just swim up n down the glass ignoring each other :(
should i use a male Mickey mouse maculatus to a female swordtail or 2 or 3 or use a male swordtail to female Mickey mouse maculatus???
<They do cross-breed freely, but whether the offspring are worth keeping is a whole other thing. Furthermore, Swordtails do tend to be more predatory towards their fry than Platies.>
what setup would work the best??
<Lots and lots of floating plants will be key -- somewhere for fry to remain safe while you collect them every day.>
thank you.
<Do obtain virgin females of the species you want, keep with the male you want for a couple weeks, then remove Hope this helps, Neale.>

Male Swordtail with no "sword"    7/16/12
Hi, WWM Crew :)
<Hello Jen,>
I am a fledgling aquarist, and am thoroughly enjoying getting hooked! Pun intended.  I have spent many hours perusing your website, and have found the information invaluable. 
I have a cycled 55g tank with some Bleeding Heart Tetras, Peppered Cory Catfish, Bristlenose Pleco, and Reticulated Hillstream Loaches.  I recently acquired my final tankmates - 3 Pineapple Swordtails.  I thought I purchased 1 male and 2 females, but have since discovered that one of my females may actually be a male.  I have attached photos.  Compared to the obvious male (with nice sword), the suspected male is a bit plumper in the body, but he does appear to have a gonopodium.  Compared to the female, he is more streamline; more colourful; and has obvious differences in anal fins. 
Would you agree that I have a male without a "sword"?  I will be returning him to get another female.
<It's quite common for males to be late developers; the sword will probably grow, in time. This is widely believed to be the explanation for why "sex changes" were reported among Swordtails for many years.>
My second question is related to my Reticulated Hillstream Loaches (Sewellia lineolata).  I did post this question to loaches.com, but have yet to get a response.  I apologize if it's a stupid question.  I've searched for hours looking for detailed anatomical descriptions on these little beauties.  I was a bit concerned that there appeared to be a white area on the female just below the mouth (above the "heart"?).  This was while they were in the quarantine tank.  It has since seemed to have resolved, and they are now happily in the 55g tank.  My question is, what exactly am I looking at on the ventral view????  I can make out the mouth - cranial to the first, see through, whitish area.  Then there is a smaller, see through, whitish area caudal to that.  I've seen it referred to as the heart.  Are you able to shed any light on this for me?
<Not sure what this is, but it's normal, so don't worry. Your main problem with these Hillstream Loaches is keeping them well fed and not too warm, but Swordtails enjoy similarly cool conditions and also eat algae, so they could get along well. Not so sure about the Bleeding Heart Tetras on this front though. Do read up on Hillstream Loaches -- they are not community fish, but fish for specialty set-ups.>
Thank you so much for any help you have to offer.  And thank you for having such an informative site to access!
<Most welcome, Neale.>

Xiphophorus; reproduction, stocking     6/4/12
Good evening! We have a 15 gallon tank with the following inhabitants: 4 zebra danios, 3 blue fin guppies, 4 White Mickey Platy's (2 male, 2 female), 3 Sunburst Wags (1 female and 2 males), and a small catfish.
<What kind of catfish? A Corydoras? They are social fish -- get a couple more, at least. Your tank is already pretty well stocked though (and I'd argue the Danios are too active and big for it anyway) so you will need to focus on water quality.>
Our sunburst wag, Momma, gave birth about 3 weeks ago; we were able to recover twelve of the babies; currently in a 10 gallon tank and thriving.
Today, we saw at least 2 new babies in the original tank! We're pretty sure they're Momma's babies because she's been behaving like she did a few weeks ago.
<Any/all of the females will be pregnant since you've added males, so I'd be open minded about who's the mother.>
She seems so stressed out right now from giving birth so soon. Can we put Momma into the other tank, with the original fry?
<If you want, for a while. But 10 gallons is too small for adult Platies.>
Also...is there a way of avoiding breeding, by say...having all females or all males of a particular species?
<For sure. Keep virgin females and you'll be fine. After mating though the females may produce more than one batch of fry, so just removing the males today may mean it'll take many months before the females are "empty" of fry.>
Thank you so much, Bryan and Kimberly
<Cheers, Neale.>

Simple question regarding swordtails, repro.     3/5/12
Hello all!
The last 10 years or so I've been keeping big cichlids and other predators.
However, a 5 day long power outage in the late fall (aka, our house went down to 40 degrees) really did a number on one of the tanks (surprisingly, only 1 out of 8 tanks had any fatalities... but that tank lost all.=(
).I've decided it was an opportune time to try community tanks again, and now have a somewhat planted (on a learning curve with those plants!)
125gallon tank with rainbows, angels, many tetras, and swordtails. With so many predators in the tank, the swordtail fry haven't been making it, and I'd like to separate the females when they're near the end of their gestation period into a 20 long that is heavily planted. However, the one time I tried this, the female went from being extremely energetic to not moving and not eating for the entire period she was down there.
<Have to be moved way ahead of parturition>
I actually thought she was dead and stuck in a plant, she moved that little. She did end up dropping some very healthy fry, but only 5 - could she have miscarried because she was so stressed?
 If a super densely planted, low light tank with frozen bloodworms
<See WWM re this sewer fly's larvae... I wouldn't use much or at all>
 being offered isn't enough to keep her calm, what is?
<A good pelleted food: Spectrum is my fave... small diameter>
Is she just nervous because it's such a change from the 125?
<Being chased, netted...>
We regularly raise fry in that tank, so it shouldn't be water quality.
Just looking for some potential changes to enact. I'm more baffled than worried, but am not willing to try to move her again because of that past experience.
<Just as. Bob Fenner> 

Pregnant Swordtail 10/05/11
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Pregnant Swordtail

I have never had swordtails of my own, but now I do, and I believe that two of them are pregnant.
<You can safely assume this once male and female livebearers have been kept together for even a few minutes.>
My question is which of the two in the pictures attached is further along?
<Impossible to say. The "gravid spot" is pretty meaningless with anything larger than a Guppy, but females do get larger around the abdomen as they approach birth. Broods are born between 4-6 weeks after mating.>
I have a 5 gallon "nursery" tank with a breeder net in it to to the pregnant fish in when the time gets closer. The fish are from this tank:
10 gallons
4 female swordtails
1 male swordtail
1 male balloon molly
1 female balloon molly
1 Bamboo Shrimp
Should the pregnant fish be kept in the nursery tank?
<Absolutely not; 5 gallons is far too small for adult Swordtails. Put some floating Indian Fern (Water Wisteria) in the tank. The fry will hide there.
Every morning, check over the plants, and net out the fry and put THOSE into a breeding trap or a nursery tank (obviously the latter only if it has a mature filter and heater).>
Another quick question. Can the balloon molly mate with the female swordtails?
<Mate yes; produce viable offspring, no.>
Thanks in advance!
<Cheers, Neale.>

Pregnant swordtail 9/26/11
My candy wag swordtail was pregnant or still is? Had gravid spot.
Exhibited behavior such as hiding, rapid breathing. Gravid spot only visible on right side, she has the "squarish" form.
<Don't worry too much about the gravid spot. This is a patch of dark tissue visible through the skin when the womb expands. Small livebearers like Guppies show this feature well, but bigger fish like Swordtails and Mollies much less reliably. Much better to go by the size of the female; if her abdomen is looking swollen, and she isn't obviously sick or constipated, then she's likely close to parturition. In any event, if you have male and female Swordtails together (or with Platies; they hybridise readily) then it's almost certain any and all mature females will be pregnant.>
So we transferred her into breeder trap in separate tank with 2 tiny babies from other batch of fry (not sure which female had them).
<Don't ever put adults in the traps. Despite the marketing, these traps aren't safe and they stress the females substantially. Instead, use the traps to keep the baby fish safe for the first few weeks when they're small enough to be eaten. Once they're bigger than that, let them loose among the adults. If you stock the tank with lots of floating plants, then most newborn fry will survive a while even alongside their parents, and you'll have plenty of time to find fry and rescue them to the trap. This approach works extremely well. Indian Fern is the ideal floating plant, but Amazon Frogbit also works well. At a push, even ordinary pondweed works!>
Anyhow overnight & after the transfer, this morning gravid spot gone. She still has the "squareish" shape & it looks like she's got bubbles inside her. Can faintly see possible eye balls? How long should I leave her in breeder trap waiting to see if she drops any fry?
<Not at all. Confining her in the trap will stress her, and likely lead to miscarriages. At the very least, newborn fry will be at severe risk of being eaten by the adult.>
Could she have aborted & if so is there anything I should do for her?
<Yes, stillbirths are common in traps, and the females can easily eat the corpses. Even if she doesn't, snails and shrimps can crawl in and eat them.>
She's still plump but doesn't seem as plump as when we put her in last night. First time dealing with pregnant fish. Had a total of 3 females, 2 have died since we first noticed tiny swimming eyeballs (fry) didn't know any of them were pregnant or which had the fry. We had 2 red velvet females with my surviving candy wag female. The 2 surviving babies are now red but still too small to join the large community tank. Thanks in advance, have a great day!
Tracey :-)
<Hope this helps, Neale.>

Fry Swordtails (Pineapple or Neon) 8/12/11
Hello I looked all over your site and I'm hoping it wasn't in there. My female Pineapple or neon Swordtail (looked at the Google pictures for both and my Swordtails look like both-so I'm not sure which one they are. They have a brown stripe down their side and they're orange on the top of their body, and I haven't seen them before in the pet store.) Anyway, She had some fry, I've tried to count them but they just don't stay in one place, (LOL) so I think I have counted them twice sometimes. So I'll say I have 12-18 fry. Now to my questions...Sorry...When do the fry get their swords?
<The males in a few weeks...>
Can they breed before their swords develop?
<Mmm, not really, no... but can as they're gonopodia develop... in a couple/three months>
Thanks for your time and have a great day!
<And you. Bob Fenner>

Female Swordtail No Longer Having Fry? 7/31/11
Hello! I have observed an odd occurrence with my female orange Mickey Mouse Swordtail. Around March, maybe February, she had a few fry one month and then the next in my old 55 gallon aquarium. Her four offspring are almost identical to her, and when I bought her, she was mistakenly placed in a tank full of Mickey mouse platies. I have two from each "litter" in my 55 gallon aquarium now.
<I see.>
However, in April we had a house fire, which was caused by the light on my aquarium (SHOCKER I know.)
<Definitely not common! Has the cause been established? Aquarium lights are generally very well manufactured, though there are some cut-price imported tanks from China that may well be questionable in quality. Tanks from reputable brands are normally designed very well, with the wiring moisture-proof. It's a good idea to use circuit breakers on the tank to further reduce any risks of electrical fires.>
She and a few others survived although the glass broke and ninety-five percent of the water was in my floor. For the next two months, she and many, many others were crammed into two small ten gallon aquariums, which was probably around 30 fish, and the majority of them were in her tank.
Anyway, now that my new aquarium has been cycled for a month, I was expecting her to have more fry. She has been with two male platies for quite a few months and has had no fry. I have read that interbreeding between platies and swordtails is common, but they have not interbred yet.
<Store-bought Platies and Swordtails are in fact hybrids between the two species. Yes, Platies tend to have more Platy genes, and Swordtails more Swordtail genes, but all the ones in the shops are mixed up genetically to some degree.>
In fact, the two males never even get close to her (she is twice their size, maybe they are scared). Is it possible she is picky about her mates?
Or could she be too old?
<This is certainly possible, as well as cannibalism in small tanks, where fry are immediately consumed by other fish.>
She shows no signs of sickness or disease, and I have had her for about five months. Do you have any idea what is going on? Thanks in advance! -Lucas
<Cheers, Neale.>
Re: Female Swordtail No Longer Having Fry? 7/31/11
I also forgot to mention she has not shown a gravid spot for months; when she was pregnant before she did.
And about the tank light, it was bought at a chain pet store, and was definitely the cause of the fire; the water from when the glass broke put the fire out, and all everything except the light was warped from the heat. The light was completely destroyed.
<Sounds a mess.>
Thanks for such a quick response!
<You're welcome. Cheers, Neale.>

Swordtail Fry 7/14/11
Hi guys!
We have some swordtail fry at different ages and they are kept in a fry 'cage' within our 125lt tank. We just wondered at what size we can let them out into the tank population? We have 3 Gourami's, two female one male, a couple Scissor tails, one female Swordtail, 10 smallish Neon and Black Tetra's. You're advice would be gratefully received!
Thank you kindly,
Claire & Pete x
<Mmm, depending on the size of the Gouramis, likely a half inch to an inch in overall length. Even then, they are the species most likely to "go after" the young Swords. Bob Fenner>
Re: Swordtail Fry 7/14/11

Thank you so very much for your speedy and most helpful response! Our Gourami's are fully grown at 4-ish inches. We did lose quite a few babies to them but put it down to nature however we did manage to save a few. The older ones are about half inch in size so will let them out soon. Thanks again for your help, from Claire and Pete x
<Welcome! BobF>

pregnant swordtail 3/14/10
what behavior does a female swordtail exhibit before she drops her fry?
<Nothing much. Shortly before parturition, female livebearers tend to retire to the floating plants you've added to the breeding tank (Indian fern is ideal). The fry will instinctively hide among floating plants away from other fish. But beyond this, the females don't do anything much. Check the floating plants each day, and you should eventually find the fry swimming there, hidden nicely among the roots and leaves. Cheers, Neale.>

Is my female sword tail pregnant? 08/02/09
I would like to know if my female swordtail is pregnant.
<You can answer this yourself! Has she ever been with a male in the last, say, two months. If the answer is yes, then she's almost certainly pregnant.>
If she is I would like to know how far along she is also.
<Gestation is 4-6 weeks.>
If anyone can tell me when she can possibly have her fry I would like to know very much.(she has a big stomach and has a black type pouch near were she poops but i cant see any eyes so if anyone can please help i would very much so appreciate it).
<On small livebearers such as Guppies, the black region around the vent becomes apparent because the uterus is forced against the relatively thin muscle wall. On bigger livebearers, including Xiphophorus species, this so-called "Gravid Spot" is difficult to see and unreliable even when apparent.>
Thanks, t-Larson
<Cheers, Neale.>

Mysterious fry 7/11/09
Around the middle of April we bought 2 female red velvet swordtails.
Around the end of May one of them died. Just yesterday I was looking at the tank (which only has a Pleco and a moonlight Gourami) I spotted one tiny swordtail fry. I am absolutely baffled at how two and a half months later there could be one fry in the tank when there was no other swordtails for the female to mate with at all, let alone a male. Any ideas?
<The gestation period for livebearers is typically 4-6 weeks depending on temperature, but females of many species can delay maturation of some of their embryos, so that some are born after 4 weeks, some more another 4 weeks later, and so on. In extreme cases, as in Heterandria formosa, this can be spread out along a period of up to 6 months. So it isn't all that unusual for unexpected fry to be found in livebearer tanks. It doesn't imply anything is wrong, and after a few months, all the embryos should have been born, and if needs be, you're free to mate your female with another male of a certain variety or colour, and expect the resulting fry to resemble that father rather than the one six months previously. Cheers, Neale.>

Xiphophorus, breeding 6/21/09
Dear Crew,
I have a pregnant red wag swordtail. What should I do to prepare for the birth??
<Ideally, fill the tank with floating plants.>
Should I take her out and put her in a different tank before she has birth?
<Transporting a fish from a healthy tank to a new one makes no sense unless the other tank is appropriate. For a single female Swordtail, that's have to be a tank at least 60 cm/2 feet in length. The filter would of course need to be fully matured, but you can do that by taking some of the media from a mature filter and putting it into a new filter in a new tank. Don't confine a pregnant Swordtail in a breeding trap; they're too big.>
She has only about a week?
<Not sure how you know this.>
until she has the fry.?
<From insemination to parturition is about 6 weeks, though this varies, particularly with temperature. Cheers, Neale.>

Please Help (Xiphophorus; repro.) 10/21/08
Hi there, I am VERY new at this and by new i mean this is my first fish tank ever. I set it all up about 3 weeks ago and got 4 sunfire platies 2 male 2 female and I love it. they are great. after reading some of the stuff on your page I kinda thought one of the platies was pregnant.
<Almost inevitable...>
I ignored it for about a week until I noticed the one i thought was pregnant was no longer "bloated" looking and sure enough i saw a little baby wedged into the pebble at the bottom of the tank.
<Cool. Do add floating plants to the tank: your "harvest" of babies will be dramatically improved.>
I figured it was dead since it had been there a day and not moving but today (a couple days later) I noticed it had moved position. So I "rescued it" from the pebble and sure enough its alive. I don't have an extra tank so I put it in a rather large Tupperware bowl with the original tank water as to not put it into shock so my question is what do I do?!?!?
<Easiest thing to do is get a breeding net and attach it to the inside of your aquarium. Assuming your tank is above the minimum size for Platies, i.e., 20 gallons or more, such a net should cause no problems for the existing fish. Feed it powdered flake food or liquid baby fish food if you really want. A bit of algae is helpful, too. After a month or so the baby will be big enough to be turned loose.>
its swimming a little in the bowl and seems to be doing just fine now that I realized its not dead. do I need to go out and buy a tank with a filter or is this going to make due for a while at least until I can afford an extra little tank or something besides a bowl. do I feed this baby fish if so what and how many babies do they usually have because I have looked and cant find anymore. but I plan on cleaning the tank tomorrow to make sure. I'm so lost and feel like I'm in over my head now. please help. thanks for your time
<Much written here about keeping, breeding livebearers; avail yourself of these resources! 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.>

Xiphophorus; behaviour, repro 8/3/08 hello again, sorry to bother you Neale, <Hello,> I swear that sending emails to you will not become a common practice of mine- I can assure you this. And I hope you don't think I'm a nuisance already (for, this would be my third question to you). <Fire away!> My platys are not sick, their tank's ph, ammonia, chlorine, etc- they're all fine. Nothing is physically wrong with my fish. My problem is simply this: I bought some new fish (I've upgraded to a 20 gallon- so don't worry I have the room). One of my new fish is a white Mickey mouse platy and he seems fine and mild tempered; he displays no aggression towards any of my fish, except one. She is a female I've had for a long time and I've grown quite fond of her. <The males will pester whatever female they deem to be "fittest" in terms of being the most attractive recipient of their genetic material. How they make those choices is complex. But in any event, what you're seeing simply means he likes this girl the most.> I'd hate to have anything happen to her. It pains me to see the new fish chase only that one female fish around. Other female fish are fine and so is my one other male. My question to you is: why is the new white male singling out only one of my fish? <Entire PhD theses are written on mate selection! Broadly speaking, male livebearers are shorter lived than the females. They are smaller, brighter colours, and often encumbered with things that make them worse swimmers (e.g., longer fins). So males have to breed quickly. Females are bigger, camouflaged, and stronger swimmers, so they can take their time and choose mates carefully. Producing sperm is cheap and easy, so males can afford to mate frequently. Females are stuck with the eggs their born with, and each pregnancy places a heavy energy demand on the female, so she wants to mate only when it is in her best interests to do so. This creates a tension between the males (who want to mate urgently) and females (who want to mate carefully). Bottom line: males will pester whichever females they want to mate with. This is why with livebearers I like to tell people to be generous about the size of the tank; to keep them in fairly big numbers to dilute aggression/harassment; to keep more females than males; and to provide lots of floating plants so that females have hiding places.> I've never seen this before. Usually when I pick a mean fish, it will attack all the fish in the tank, or at least two or three. This one is dead set on following and sometimes nipping at just one fish in particular. <Does happen.> Will this behavior go away with time? <No guarantees.> Should I give this situation time? <Up to a point, but if she's having trouble resting and feeding, then that's going to cause problems ere too long.> Will the stress of constantly being chased back and forth kill one of my favorite fish? <Conceivably.> I am very worried. I would like to keep the new fish, as he is very pretty and I want to keep a good female to male ratio so that my one dominant female doesn't become too possessive of my one male. But I understand that if the new fish's behavior is not something that will go away, I will have to return him to the store. <If you have space, I'd add some more females. I can't remember how big your tank is, so be sensible about this. But adding females usually benefits the livebearer aquarium. Adding decent sized floating plants (e.g. Indian Fern) would be another cheap-and-cheerful solution that might work.> Thank you for taking the time to read my questions and I hope I'm not a nuisance. The questions on your site don't really seem to be geared toward platy behavior so much as platy illnesses. I figured a direct question to you would be a better avenue. <Indeed.> Thank you so much! <Cheers, Neale.>

Re: Xiphophorus; behaviour, repro 8/4/08 Neale, Thank you for responding to my questions. I had a feeling it was something to do with fish affection but I wasn't sure. Better to be safe than sorry, right? <You mean fish aggression rather than affection, I suspect! And yes, better safe than sorry.> I do have room for three more fish and this time I'll be more careful as to what sex of fish I choose. My tank probably does need more hideaways and I'll work on that as well. Again, thank you for all your help! <Sounds like a good plan. Good luck! Neale.>

Weird Swordtail Pregnancy? 4/8/08 Hi, I have a Swordtail that has been pregnant for about 2 months now, and I have a few questions. Well, first of all, isn't 2 months a little bit long for a Swordtail to be pregnant? <Does vary, but more than likely has produced fry and since been eaten. Unless you have lots of floating plants, the chances of fry surviving more than a few minutes is next to nil.> And I was able to see the little red heads of the fry in her, but now they turned BLACK? What's that supposed to mean? There is still a light gravid spot. Im just worried that something is wrong... <Sometimes livebearers do fail to deliver the fry, or something goes wrong and the embryos become infected. The results are unpleasant, and I've seen a poor female Halfbeak die this way. There's no fix. In the meantime, let's hope that isn't the case. Do treat for constipation, in case that's a background issue or even the cause of the swelling. Live daphnia and brine shrimp will work as a laxative, and stop using any dried foods for a couple weeks. The "gravid spot" isn't really visible on Xiphophorus spp. Let's understand what this spot is. In small livebearers (particularly guppies and mosquitofish) as the embryos develop the uterus pushes against he muscle walls around the anal fin. The result is a certain degree of transparency, and this allows you to see the dark uterus inside the fish. In fancy livebearers there is extra pigment that reduces the transparency, and in Xiphophorus spp. the muscle wall is so much thicker that even less light can get through. The net result is that the gravid spot isn't something to worry about with most medium to large livebearers. Instead, concentrate on the overall chunkiness of the female.> Thanks, Bekah <Cheers, Neale.>

How Pregnant Is My Swordtail? 03/10/08 Hi, I purchased a Swordtail yesterday, and I found that she is pretty pregnant! (Woohoo!) But my question is, how far? I can see the eggs (they are red) and I can also see a few little black dots near the anal fin, and, I can see, little teeny fry in there I think. (The mother is an Assorted Swordtail, so she if VERY translucent.) So, to narrow it down, about how long do you think until she has her fry? Thanks s-o much, Bekah <Short answer is absolutely no idea. Gestation period in Swordtails is typically between 4-8 weeks, depending on the environment. If you can see the fry already, she's presumably not far from delivery. Make sure the tank is FILLED with floating plants, otherwise they will get eaten. And NEVER, EVER put a female livebearer this size in a breeding trap or net. If she doesn't jump out, she will get stressed and miscarry. Every morning, check the floating plants for fry, and then remove them to another aquarium for rearing. Cheers, Neale.>

Breeding Swordtails? 03/04/2008 Hi, I'm a first timer at breeding fish, and Swordtails are the ones that really caught my attention. <Breeding fish is one of the best ways to expand your hobby, and is perhaps the ideal test of your fishkeeping skills. Do read this article for information on breeding fish generally. Most livebearers are much of a muchness in terms of breeding. http://www.wetwebmedia.com/FWSubWebIndex/fwbrdgmonks.htm > In my 30 gallon tank, I have two Silver Angelfish, four Peppered Corydoras Cats, one Dwarf Gourami, and one Oto. I have been scouring the internet for information about breeding Swordtails, and there are some questions I just can't find. The first question I have is, what should I put the fry in? <The pregnant mothers should be kept in their own tank. Trying to breed fish in community tanks is really a hiding to nothing. The best you can do is try and save any fry you find, but in all honesty you'll be finding one or two rather than a whole brood. Angelfish especially are notoriously good at finding and eating baby fish: Angelfish evolved to search the surface of the water for insect larvae, and so are pre-programmed to "seek and destroy" baby livebearers!> Some people say nets, but someone else will say that nets stress their fish out, and the mom will jump out a lot. <Never, ever put anything as large as a Swordtail in breeding trap or net. Breeding traps should be used exclusively to protect the fry; none of the commercially available nets or traps are big enough for adult livebearers. Yes, they get stressed and miscarry, and yes, they jump out. Save your pennies.> Some people say that those plastic breeder boxes work well, but some say that the boxes don't work out for them. Got any ideas on what I should use? <Simple as this: get a 10 gallon tank. Put the pregnant female in there, together with lots and lots of floating plants (real or plastic, as you prefer). Keep the tank covered! Wait 4-6 weeks. Look for the babies, and when they appear, remove the female.> My next question is, would it be OK to keep the fry in the breeder tank/net until they are big enough to go into the community tank? Or is it imperative that I get a 5 gallon? <A 5-gallon tank is too small really for anything much, and I wouldn't waste your money. The price difference between that a 10-gallon tank is minimal. The smaller the tank, the less value for money. Your 10-gallon tank need be only very basic. Glass box, a glass or plastic cover to stop the fish jumping out (get a glass or hardware store to cut you a pane of glass to size if you want -- very cheap), air-powered sponge or box filter, heater, floating plants. That's it. And trust me, you'll see the value, because you'll have dozens of baby fish on the go, and every time you sell them to the pet shop you'll make some money! Baby fish need to be maintained for about 3 months before they are big enough to mix with community fish or sold to pet shops.> What should my water quality be? <Perfect; baby fish grow slowly or simply die if the water is poor.> My water right now is: Nitrite/Ammonia: Good PH: 7 Water: Hard <Try and raise the pH and hardness a bit, e.g., by adding some crushed coral to the filter. DO NOT mess about with "pH up" products!> I went to a pet store to have my water tested, and this is all the info they gave me. I know that my PH is supposed to be 7 (thank goodness!) I heard, that if I want to raise baby fish, my water should be soft, is this true? <No; swordtails want water that is hard and basic; ideally pH 7.5, 15+ degrees dH.> Thanks so much! -Bekah <Cheers, Neale.>

Swordtails, repro. mostly 2/25/08 Hello WWM crew: I really do appreciate your site; it has been invaluable on several occasions. This time, however, I am truly puzzled. A couple of months ago, I bought four small neon swords (1 male, 3 females) and put them in my FW 20 gal tank. They all appear to be doing well and have grown appreciably. Since then, I have been watching for offspring but haven't seen any. <Some livebearers are intentionally and not sterilized...> This may be problematic. Although the tank contains several fair sized plants, a few rocks, and some large driftwood for hiding places, it is also inhabited by 5 green tiger barbs and a 4 inch (or so) <Mmm, these could be eating the young... as could the Swords themselves> Pleco. The swords seem to like the barbs; they all swim together in quite a congenial fashion. But you can see that fry may not survive all this activity for long. Anyway, one of the female swords has had a gravid spot all along and still does. The other two, however, are now both growing gonopodia (or gonopodiums?) of their own - definitely no spot. So what do I have? Do I have a sterile male? or 3 males, 1 female? <Looks like at least the latter... Often Swords et al. fishes (e.g. barbs...) are "forced" to change sex phenotypically... usually the other way around (to look like males)... In your case, perhaps these latter day males are simply finally turning into such... Livebearers raised in large system circumstances can grow fast, be larger body-size wise, before developing sexually...> Do I return this batch to the store - it doesn't seem to be their fault? I realize that they all came from the same batch and so mating them is not advisable but I can't see how this could be a factor in this situation. <Mmm, could return... Might separate out the one female, raise some young elsewhere...> Anyway, I hesitate to buy another male - would he be ostracized by the others? <To some degree, likely so> I don't particularly want a lot of rivalry in the tank with a lone male - either the current one or the new hanging in a corner somewhere being picked on. Would I be better to add more females and hope that someone can do the necessary as it were? <Mmm, actually, a 20L is not very large for Xiphophorus...> Or should I just wait and let these sort themselves out? <Yes, this is what I'd do here... along with possibly separating the "pregnant" female> Also would it be better to get a female other than neon - say a marigold? That is, would the offspring (if any ever materialize) be healthier in any way? <Mmm, possibly... though all "sports" of popular swords are the same species, some heterosis/hybrid vigour, may be had by a bit of out-breeding> Rosemarie Mart <Please read here: http://wetwebmedia.com/FWSubWebIndex/swordreprofaqs.htm for a bit more background. Bob Fenner>

Pregnant swordtail -11/18/07 Last night I noticed my swordtail had had babies. I only found two babies roaming my tank, but its obvious that she is still pregnant. I'm just wondering if they were premature births, and if there are more to come, or any other reason. Thanks Jeff <Jeff, this is a case of a little from column A and a little from column B. Livebearers will sometimes release fry a few at a time over several hours or even days. But they can miscarry under some circumstances, and premature fry will have a chance of survival depending on how premature they were. In addition, some of the newborn fish may have been eaten, in which case you won't have seen them. It is quite common for young livebearers to have small broods, the broods increasing in size as the female fish matures. So there's a bunch of things going on. In the meantime, doing all the usual things such as installing lots of floating plants will maximise your chances of rescuing fry. Cheers, Neale.>

Baby swordtails 10/26/07 hi I have two ten gallon tanks and I have had many babies. the fish that had the most babies are my sword tails. I got my two sword tails and the male has been ferry ferry (friendly) to the female. is it possible two have black swordtails that have babies that are a different color? <Yes. If nothing else, there's no guarantee the black female was fertilised by the black male; she could quite easily have been fertilised by another Swordtail of another colour. On top of that, not all swordtails will "breed true", especially if you bought them from a "pick and mix" batch of Swordtails rather than pure-bred fancy Swordtails guaranteed to breed true.> she had two batches of babies and is pregnant again. the first time she had I don't know how many babies but I caught six and three are still alive and healthy. those are two months old. they are all alive. now the swordtail had more and there are four. two are black like the others and two are plain and kind of yellowish with no marks. <OK.> can you tell me if my swordtail had a different color baby and if her next batch will be different too. Jon <No idea what your baby Swordtails will turn out to be next time. In theory, livebearers can only store sperm for up to six batches of fry, so after about six to nine months after being purchased your female Swordtail will have used up any sperm acquired by any male other than the ones you have now. So from that point onwards you can expect her to only produce broods by the male in the tank that you have. But genetics being what it is, it is perfectly possible for fish of one colour to carry the genes for two different colours, so there's always a chance you'll get a mish-mash of colours in the offspring. This is why breeding livebearers to a high quality is difficult, and a lot depends on the quality of the fish you start off with. For the best quality stock, you really need to get in with your local aquarium club or national livebearing fish association. Auctions of "virgin" fish are routinely held, and from these fish you can start a proper breeding programme. Cheers, 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>

Pregnant or not... Xiphophorus... - 09/24/07 I have spent approximately 6 hours searching your website for an answer to my question/problem so as not to be redundant to what has already been stated/asked. <Wow! Six hours...> I feel confidant enough to now e-mail you with my question without being a bother. I have a new tank that I completed the nitrogen cycle and aged for 6 weeks per all gathered information before adding the "sacrifice" (my term) fish to help get all conditions ideal. They all have survived (3 mollies) and are still very happy. <Hmm... how did you cycle the tank for the first 6 weeks? Did you add an inorganic source of ammonia? Simply waiting 6 weeks without adding either fish or ammonia won't cycle a tank.> I waited another 2 weeks to add plants. Another 2 weeks to add my 4 red velvet swordtail (1M 3F). They have been settled in their new home now 5 to 6 weeks. I test 2 or more times a weeks currently but during the nitrogen cycling I tested daily. Rather than including all my numbers from the beginning I will just state all readings have been within the norm for my swords and tank conditions per all published data. <Ah, the numbers *do* matter. You see, a lot of aquarists misunderstand what "the norm" means. The goal with swordtails and mollies are as follows: 0 ammonia, 0 nitrite, <50 mg/l nitrate, pH 7.5-8.0, hardness at least 10 degrees GH and ideally 15-20 degrees GH.> My test kit is the largest one, testing the 8 mentioned (in all I have read about) conditions. My water stays at 72 degrees F with out a heater though I do have one. <A bit too cold. The normal temperature for these fish is around 25C/77F. Lower temperatures increase the likelihood of health problems.> One sword looked as though she would pop any day when I got her. Now 1 more female looks the same. The third one still slender. The male just this week started being amorous so I guess is now of age. <All sounds normal. Gestation is temperature dependent, so if your fish are being kept at too-cold a temperature, they may take a long time to produce viable broods of fry.> My swords are red velvet and very deep red in color. I really hunted until I found the "old timey" ones and not the faded out ones (orange) you mainly see today. I was told they were wild caught and not from breeder tanks where the genes they pick up from inbreeding reduce their pure color-how true this is I don't know, but I do know these 4 look like the red velvets I had years ago. <Unlikely "wild caught" -- wild Swordtails are green with orange/yellow/blue longitudinal bands, nor bright red.> Neither of the "pregnant" females have the "gravid" spot. <Not visible on Swordtails, especially not brightly coloured ones. The gravid spot really only applies to small livebearers -- guppies, Gambusia, etc.> Since the first one looked ready to deliver upon arrival and the second one now looks like the first one when she first came home, are my girls just extremely fat or could some conditions just be extending the pregnancy (don't know if that is possible, but knowing they can change sex and choose when to be pregnant with one sperm donation I question gestation length). <Sex change in Swordtails has not been proven scientifically (if I recall correctly). If it happens at all, it is incredibly rare.> Could their deep color be 'hiding' the normally obvious gravid spot (more familiar with what guppies look like). <Yes, plus thicker muscles around the abdomen.> When they are in the light just right you can slightly see through them enough to distinguish what I assume in the solid internal organ area, but just barely. Is there always an obvious gravid spot in swords, or could their deep color mask the obvious? I am a bit OCD which probably is obvious and I am ready for babies-why are the two "pregnant" ones not delivering, or at least showing the gravid spot. <When they're ready, the babies will come. In the meantime, make sure you've thickly planted with floating plants such as hornwort. Otherwise the babies will be eaten minutes after they're delivered. Under no circumstances place a female in a "breeding trap".> (PS my tank is a 35gal standard hex moderately to heavy planted-subjective-they diet on bloodworms, algae tabs, Tetra color flakes, High vitamin flakes, Tubifex worms, fresh orange, and peas. <All sounds fine. Do consider switching out some of the "designer flake food" for algae-based flake. That's what livebearers really want. Keeps them very healthy.> I rotate the flakes every other day on one feeding and then rotate the other foods on the second feeding. All food is gone with-in 90 seconds except the algae tab which takes up to 30 min. and the same goes for the Tubifex cube.) Long letter to just ask a few questions, but did not wish to forget giving any information that could help coming to the proper answers. Thank you so very much for your time. Victoria <Hope this helps. Good luck, Neale>

Swordtail repro. 9/23/07 Hello Crew, I've looked through the website, and I don't think you have anything that pertains directly to my question, so here goes. I have six 6-week old swordtail fry. All of them seem to be doing well in that they are eating and swimming around and enthusiastically responsive to the lid coming open for feeding time. They are kept in a 10 gallon tank, temp around 78 (the thermometer is sadly not adjustable). I feed them three times a day with fry food and keep an eye on them to be sure everyone is getting their share. I interchange Wardley Essentials Small Fry Liquid Food and Hikari Tropics First Bites, to try to be sure nutritional bases are covered. The Wardley food is min. 6% crude protein, min. fat 3.5%, fiber max 0.4%. The First Bites is min protein 48%, min. fat 3.0%, max fiber 2.0%. I only just noticed the difference in protein levels. Is one or the other preferable? Among the six, only one fry seems to be having trouble. It and another fry were the two smallest, approximately the same size, but whereas the other fry has doubled in size recently, the smallest fry has not. I removed all six from the tank today to scrub out some algae that was getting a little out of control, and to exchange their small shelter plant for a bigger one to better accommodate them. (I realize removing them from the tank might cause undue stress, but I've learned I'm guaranteed a freak out if I try to stick my big hand into their quiet little paradise and it didn't seem fair with all that I was planning to do.) This is the first chance I've gotten to look at all of them in a small, confined space. The smallest fish has a strange crook. At first I though it was a lump, but the axis of the fish seems to literally bulge to one side before continuing in the usual linear pattern. Other than this deformity and the small size, this fry seems to be doing well: swimming motions aren't affected and it continues to dart in for food among it's siblings (now 2-3x as big). Is there anything I can do? Potentially a nutritional deficiency? Or a congenital problem? Any help would be greatly appreciated! :) Lauren <Hello Lauren. Rearing livebearer fry is generally problem-free, provided you "go by the numbers". The main things are these: Firstly, they need 4-6 meals per day for optimal growth. Flake food is fine, but I recommend algae-based ones as far as possible. Hikari First Bites is an excellent food to begin with, but after a week or so you should move onto crushed Spirulina flake or similar. After about a month or so you can scale this back to 3-4 meals per day, and then down to just two once they reach 15 mm or so in length. "Meals" can include live algae, so dumping a green algae-covered stone from a clean pond might well last them all day. In other words, "scrubbing out the algae" is insane -- your livebearers need this stuff for good health, so leave it in the tank! Blue-green algae they won't eat of course, but the other kinds are valuable sources of nutrients. Secondly, water changes need to be frequent, because the build-up of dissolved metabolites reduces growth rate and promotes poor health. At least for the first four critical weeks, 10-25% water changes daily are a good idea. I find placing an old ice cream carton by the rearing tank works well. Every time I'm in the kitchen (where the tank is kept) I slurp out one litre of old water and pour in one litre of new water. Zero effort, and it helps to keep things sweet in the tank. Thirdly, livebearer fry need shade. Floating plants are idea, but even a bit of polystyrene cup will work fine. The shade gives them somewhere to hide and rest from the heat produced by the lights. In open tanks, the instinct of livebearer fry to swim to the top of the tank causes them to bake under strong lights. So shade helps. Finally, water chemistry is important. Livebearers almost all do best in hard, alkaline water. You're looking for 10+ degrees KH, 15+ degrees GH, and pH 7.5-8.0 for best results. Malformed fry can happen (do happen) in fish broods quite commonly, but background problems, like water chemistry make them more common. Under normal circumstances, they shouldn't account for more than 1 in 20 or 1 in 30 fry. Hope this helps, Neale>

Swordtail Fry with Ich. HELP!!! 9/3/07 Hi, recently I purchased a trio of Swordtails from Petco (bad idea I know... but they were on sale for a buck each, I couldn't resist!) anyway I put them into a 10 gallon QT, after the second day the females started showing signs of Ich, I dosed the QT with an herbal anti-ich medication <These don't work...> I have had success with in the past, and performed 50% water changes every other day for 4 days. after the 5th day of treatment I noticed a few little orange specs hiding around the heater, it seems one of the females had given me about a half dozen babies. I immediately added some java moss from the display tank to the QT for the babies to hide in, and after two more days the parents were showing no more signs of ich, so I moved them to the display tank, I didn't want the babies to become snacks after all... anyway the fry seemed to get all the food they needed out of the java moss for the first few days, after which they started taking Hikari micro pellets, they have been eating well and growing fast for about 10 days now, but two days ago I noticed some signs of Ich of three of them, two had just one spot each, but one (the smallest, and the one with the least color) has at least 6 spots, I stopped adding the ich medication in with the water changes after I removed the parents. I have been slowly bumping the temperature up for the last 3 days, it is at 84 now, <Good technique> and the fry all seem to be hanging out within a few inches of the heater, although the increased heat doesn't seem to have done anything except stop the ich from spreading further. are the fry too young to put in water dosed with ich medication? <Mmm, depends on the make-up of such... I would use only half doses of anything with metal or Malachite Green content... and raise the temp. up to 86 F> what can I do to make sure I don't lose my babies??? Thanks. ~Bryan <And you have read here: http://www.wetwebmedia.com/FWSubWebIndex/fwich.htm and the linked files above? And the FAQs on Swordtail Disease? Bob Fenner>

Re: swordtail fish... Fry 7/27/07 Hi Neale: Good morning. sorry to bother you, I would like to now if I can put the fries that are about 2 weeks old in the 10g tank with 1 Gourami, 1 Plecostomus (don't' know his name in English) 2 angels 3 guppies. The fries are in a small 1.5g bowl with some live plants in and there's about 15 of them. also my husband turn off the air pump at night and I don't know if the Plecos can live with the air from the plants. have a nice day. Mely <Hello again Melida. No, your plan will not work. Angelfish in particular eat livebearer fry. Angelfish can eat any fish the size of a Neon Tetra or smaller -- so only add the baby swordtails once they are that size. This will likely be a couple of months, at least. Plecostomus catfish are usually fine with livebearer fry though, and guppies should ignore fry more than a few weeks old. You can switch an air pump off safely PROVIDED it is not powering the filter. Aquarium filters must run 24 hours a day. If all the air pump does is make bubbles in the water, then this is not so critical. What matters is that the water is [a] filtered and [b] circulating properly so oxygen is distributed around the tank. Hope this helps, Neale.>

Hello! I have a few questions about swordtails! Beh., comp., repro. 07/01/07 Dear Crew at WetWebMedia Hello, my name is Oksana. I have two swordtails, a male and female, and a 1 1/2 gallon tank. (Yes, I know, terrible, but my parents won't let me get a bigger one.) Bob, the male, has been living a few months in my possession, seems very healthy. Betty, (The female, I just got her today, June 30) seems healthy too. Before Betty, we've had male swordtails, and Bob, being the dominant one, has always shown a little aggression toward the smaller and weaker ones, and unfortunately, they perished. So anyway, Bob was left alone. The problem is, is that Betty is pregnant. We got her pregnant already from the fish store, and Bob keeps nipping at her. Not full class "bites" just nips. She chases him away of course, but I keep wondering if that's normal swordtail behavior. I have read most of your pages in breeding swordtails, but do you have any extra advice? The local pet shop has already to take in the young fry when they're a few months old, but I have a question on that too. How fast do fry mature? I have seaweed in my tank, a filter, and a hiding place, (Yes, I wonder how they all fit and the fish still have swimming room...) so I don't think I need to take the female out when she gives birth. Any other tips on what to do will be fully appreciated. Thanks very much, Oksana <Greetings. Yes, 1.5 gallons is far too small for swordtails. A 20 gallon tank would be my recommendation for fishes as large and active as these. Males are aggressive, and in small tanks it is safest to keep just one male plus 2-3 females. Females do get harassed by males. There's nothing you can do to prevent this in a tank as small as yours. In a bigger tank, you can rely on plants and rocks to give the female security. But in a small tank, she has nowhere to hide. Long term, the male will likely kill any fry that appear as well. Do not, under any circumstances, place the female in a breeding trap or breeding net. Swordtails are too big for these, and get stressed. Worse case, they die, but more usually spend all their time thrashing about trying to escape. As you know, swordtails are very fast and extremely good at jumping. The ideal when breeding livebearers is to place the female into another tank where she can deliver her fry safely. Good luck! Neale>


Sexing swordtails 6/6/07 I have about 30 or so swordtails that are about 5 months old. None of them have showed signs of male/female. <You don't sex swordtails by their tails. Look at the anal fins: the females will have triangular anal fins (like those of other fish) but the males will have crooked anal fins. As a general rule, male fish tend to grow more quickly than female fish, so often the bigger ones will be the males, but this is a rough thing and not very accurate. At 5 months old they will be approaching sexual maturity, so unless you want inbreeding (and you don't) you should separate the sexes soon/now.> How long will it be until I can tell the difference/see the sword? <Right away. Do what I told you.> THX. <Sigh... another person using "Text-speak". Is real English too much to hope for any more? Cheers, Neale> <<Heeeee... yet another lesson in "tolerance". RMF>>

Swordtail/Xiphophorus repro. 04/22/07 hi there, thanks for taking the time to read this I have got a swordtail female. She is a lot larger than the other two I have, what is the best way to tell if she is pregnant? if you could help me that would be great <Short answer: has she ever been with a male swordtail? If the answer is yes, chances are she is already pregnant. Something called the "gravid spot" is often mentioned by livebearer breeders. This is the darkly pigmented peritoneum around the developing fry being pushed against the body wall. It is visible around the back half of the abdomen. In swordtails though, this isn't easy to see compared with, say, guppies, because swordtails are larger, more muscled, and have stronger colours.> cheers. john <Cheers, Neale>

Swordtail pregnancy, no useful data 4/17/04 In late February I bought 2 pineapple swordtails, one make and one female. I have them in a 10 gallon tank along with 5 other smaller fish. When I first bought the fish the female was the same size as the male, but in the beginning of march she started getting really fat and I assume she is pregnant. <Likely so> Last night I opened the top of the tank to feed the fish and my female kept swimming to the corners of the tank and trying to jump out. I put her in the breeding net for a couple hours but she seemed to be stressed so I let her out. I cant see any eyes or anything, but that may be because she moves too much for me to get a good look. How can I tell if she is going to give birth soon? Her eating habits are still normal from what I can see. <Mmm... what is your water quality like? Tests for? Particularly nitrogenous compounds? What re foods, feeding, maintenance? Have you read here: http://wetwebmedia.com/FWSubWebIndex/swordreprofaqs.htm and the linked files above? Bob Fenner>

Dark Colored Swordtails~ pregnant? Likely so... 2/20/07 Hi, <Hello - Jorie here> I just recently purchased black swordtails, male and female. They're just beautiful, they seem to be adjusting quite well. the male is very kind, he hasn't harassed the female at all and backs off if she tries to get away. <Seems like you got a mild-mannered male livebearer - you're lucky. Do keep a close eye on the pair, however, as generally, it's best to keep livebearers in 4:1 female: male ratio (provided that you have space for the additional fish).> As the female is dark, I am unable to see a gravid spot. <I understand.> Also, since I just bought her 2 or 3 days ago, I don't know what the normal size of her stomach is, so I cannot tell if it is swollen. She is fairly active, and eats well, she doesn't lay on the bottom, but kind of just hangs out there when there's nothing going on, and the male likes to stick around. <All normal and healthy swordtail behavior.> I have heard they are like guppies in that they breed like crazy and are probably pregnant when you purchase them, but I can't tell with her. None of the males that were in with her and the other females in the tank were... <weren't?> ...harassing anyone. <Female livebearers, including swordtails, are generally pregnant any time they are kept with males. Additionally, I've read that livebearers can store sperm for up to 6 mos., and basically later self-impregnate at-will. In any event, even if the female swordtails at the shop were never kept with males, now that you have combined the two, she'll very likely soon be pregnant, if she isn't already. The gestation for most livebearers is approx. 4-6 weeks. Best thing to do is just watch her closely, to ensure the male's not harassing her, and that she continues to behave as normally as she is now. When it comes time for her to give birth, DON'T use a breeding net or breeding box, as these are very stressful for fish. Allow her to give birth in the main tank, so long as there is lots of cover (decor, plants, etc.), or, alternatively, you can put her in her own 5 gal. tank until she drops her fry, then if you want to raise the fry, you can do so in that smaller tank.> Thanks for your time. :>) <You're welcome! Best regards, Jorie>

Swordtail repro., systems 1/11/07 I have a question about my 55 gallon FW with Live plants tank. The tank has been cycled over 3 months using BIO-Spira, and currently have 2 Swordtail females, 2 Female Platies/1 male, 5 Corys and a Pleco. Water is Ammonia-0, Nitrite-0, Nitrate 25-30ppm, <Mmm... do look into keeping NO3 under 20ppm... Read here: http://wetwebmedia.com/FWSubWebIndex/fwnitrates.htm and the linked files above> PH 8.0. <A bit high... could be dangerous in the event of a nitrogenous anomaly> Anyway to make a long story short, I bought the 2 swordtail females with one being very pregnant, and the other not so. The very pregnant one still looks the same after a little over 3 months, <Mmm, not pregnancy... "just" fat> however, the other is about the same size pregnant now and I found one baby about a week ago, but shouldn't there be more? <Mmm, yes... Xiphophorus give birth over day's time usually, but it may be that either the other young were consumed... or are hiding effectively from you> I'm just wondering if she has some kind of problem with the babies in her, or maybe they aren't developing correctly? <Yes, this is a possibility as well> Anyway I haven't had any losses just wondering if I should try something, as I have a 10g Nursery. Also two of the Corys are looking pale, and wondering if they like a different PH than 8.0+. Thanks <Not good to move livebearers when they're close to parturition... and the pH... might be adjusted... via water used/stored for changes... Please read here: http://wetwebmedia.com/FWSubWebIndex/fwph,alk.htm and the linked files above. Bob Fenner>

Re: Female Swordtail ready to give birth 12/15/06 Hello again, <Hi Mary!> I have two pregnant female swordtails, one is very close to giving birth. I have set up a 10 gallon tank, which I tried to cycle a few weeks ago but put bio Spira in it without adding any fish and my ammonia levels spiked and I could not get it down without doing a complete water and filter change. All the levels in the tank are now great but I am afraid of putting the mommy in a brand new uncycled tank. <I would suggest taking 5 gallons out of the community tank that the pregnant mom is now in and putting it into the 10 gal...that should sufficiently "seed" your tank.> There are currently no fish in the 10 gallon. The pH level is exactly the same as her current tank (a 36 gal. with 4 swords -the 2 pregnant females, 1 very happy male, the 1 remaining baby sword and 4 Corys) and the temp is very very close - within a few tenths of a degree. <Parameters are very closely matched - that's great. Again, I suggest filling half of the 10 gal. with water from the 36. Then, you should be able to put the pregnant female in there to give birth.> In the 10 gall. I have grass on the bottom of the tank and plants throughout (all plants and grass are silk and plastic) and a net over the filter so as not to suck up any babies. <Sounds like a great birthing setup.> The last time I had a mom give birth she was attacked (lost a chunk of her tail and got bit on the side) and she died about two weeks after giving birth. She was very pregnant when I bought her - she gave birth two weeks after arriving here. I don't want this mommy to die too. <Understandable. I think the last episode was a fluke, and don't expect the same thing to happen. You have prepared a great birthing tank, and I would expect things to turn out just fine!> Am I better off #1-leaving this mom in the main tank, #2-putting her in the net breeder (The baby saver) in the main tank, or #3- moving her into the 10 gallon tank? <I abhor breeding nets - I think they are very stressful on the pregnant fish. If it were me, I'd throw the thing out and never think of it again! I think option #3 is the best choice, if you want to ensure the fry survive. If you don't plan on raising the fry, then leave the mom in the community tank, but I imagine you went through all this trouble to make a safe-haven for the babies, correct? In any case, once you've replaced 50% of the 10 gal.'s water with "old" water from the 36, I think you're all set to go, and ready to transfer the mom into that tank.> If you say that #3 is best would you please let me know about acclimating her and if I should use bio Spira and anything else I should be doing to make her time as easy as possible. <Not necessary with the water replacement method I mentioned above. Of course, keep an eye on water parameters, and do future water changes as necessary. Fry are more demanding than their parents with regard to water parameters, so be sure to keep the water clean!> Oh, I did buy and prepare a tank divider for the 10 gallon tank to separate the mom from the babies once they are born so she does not have to be moved back into the 36 gallon tank immediately. <I've not used this type of divider before, but have heard of problems with the tiny little fry managing to get stuck against the sides of the tank...just be aware of this. I've never had a parent livebearer eat his or her own fry, so I generally allow the mom to remain with the babies after giving birth. Your method (with the divider) may work just fine, I just wanted to warn you of what I've been told!> Thank you so much for your time and expertise! Mary <You're welcome, Mary! Sounds like you are taking great care to prepare a lovely home for the mom and babies...not much else for you to do at this point! Sit back, relax, and enjoy your fish. Best regards, Jorie> Re: Female Swordtail ready to give birth PART 2 12/16/06 Thank you so much Jorie. I'm about to do the water transfer. As the last time, I so appreciate your help!! I hope you have a wonderfully joyous holiday!! <Same to you, Mary! Let us know if you need further assistance, Jorie> Sincerely, Mary

Swordtail Mating Conditions 12/13/06 Dear Crew, <Koda> I was wondering the ideal conditions for swordtail breeding, I had a male and 2 females, but the male died of starvation/stress (he never ate, always chasing the females). Ever since, my larger female grew a sword and today, she has started to try to mate with my smaller female, <Mmm... Xiphophorus can indeed change sex... phenotypically as well as functionally> who refuses to mate, constantly swimming rapidly in circles around the two fake plants, and I need to know how to get the two to breed, or how else to have fry in my tank. In case this helps, it is a 10 gallon with 1 blue Gourami, 2 dwarf gourami's and 1 sucker fish( I think it's called a Poeciliid). <Mmm, not this last... is a family of Live-bearing toothed carps... Part of your trouble here is the size of the system... Swordtails can get quite large, need room... It may well be that there is also some negative interaction going on with the Blue Gourami... If you wish to breed Swordtails, I'd get/use a twenty or more gallon system, use multiple males, with a greater number of females, assure that your water is moderately hard, alkaline and not too warm, do regular, weekly water changes, provide sufficient fresh meaty food content in their diet... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/swordreprofaqs.htm and the files linked at top.> Thank you for your time. D. Throne <Welcome. Bob Fenner>

Pregnant swordtail - where to give birth, raise fry, etc. 11/30/06 Okay thx. I have a 5 1/2 gallon I'm keeping my babies in right now...if I put the red platy in there to have the babies is that good? And if it is, where should I put the rest of my other babies that are in there now? Because she would just eat them when she's just pregnant and not having them yet. Just get a smaller tank for the rest of the fry that I already have? Would a divider work? Or do they not make any for 5 1/2 gallons? And I'm only 13 years old, so sorry if I'm asking too many questions. <Hello Sean, you've got Jorie this time. I've read this thread from the beginning, so I think I'm up to speed. In any case, I've been keeping livebearers for several years now, and have never seen the mom eat her own fry (or any livebearers eat their own kind, for that matter). I do know that it can happen, but in my personal experience, it isn't that common. I use a 5 gal. tank to allow the mom to give birth, then grow out my fry for a couple of months; then, they usually get moved to a 10 for several more months. All of this is assuming I plan to keep the fry in question - you'll soon find out that livebearers are almost *always* having babies (gestation period between 4-6 weeks), and you'll quickly run out of room for the newbies! Otherwise, I simply allow the births to happen in the community tanks I've got - sometimes, provided with adequate cover (plants, decor, etc.) a couple will make it past the boesemanni rainbows in my FW tank, and the knight goby in my 29 gal. BW. I'm not a fan of breeding/birthing boxes, as Bob mentioned below, these can tend to stress the fish, and that's the last thing you want to do to a pregnant mom. Best to leave well enough alone and allow nature to take its course. Have plenty of cover (decorations, plants, etc.) for the fry to hide in, and you'll see "survival of the fittest" in action. Believe it or not, I have one 2-3 molly juvie who was born in a 10 gal. QT with a knight goby (huge mouth!) along with his brothers and sisters; the goby ate all except this one. In any case, unless you want to set up an elaborate breeding setup (birthing tank, grow out tank, main tank(s) for when the time comes), I'd suggest allowing the pregnant platy to have her fry in the 5.5 gal. Of course, I make no promises, but as I said, I've never seen a female livebearer eat fry of her own kind. Best of luck, Jorie P.S. When you send us e-mails, could you please use proper capitalization and punctuation - I know it's the "trend" to use e-speak, but since we post our replies for all to see, someone on this end has to re-type, correct the original e-mails when they arrive in that form. Thanks!>
Re: Pregnant swordtail - where to give birth, raise fry, etc. 12/1/06
Wow! Thank you for all this information. But, just one thing...I have 11 swordtail fry in the 5.5 gal. So, if I put the pregnant Platy in there, then she will eat all of my other swordtail fry. So, I'm asking where I should put the other swordtail fry (in the 5.5 if I put the platy in there to have her fry), or should I just let the Platy have the babies in the comm. tank (because of the swordtail fry in the 5.5 gal.) Thanks for all your help and sorry for using all the e-speak didn't mean to cause any trouble =/ <Thank you for your English consideration. The parents/young all need to be separated to assure the fry's absolute safety. Reads like you need another tank/container. Bob Fenner>
Re: Pregnant swordtail - where to give birth, raise fry, etc. 12/2/06
When you say "container", what do you mean? Also, what is the bare minimum I can put the young/mom in? Because I don't want to go out and buy another tank and filter. I now only have 8 fry left about 2 weeks old. <Mmm, something that holds water... a tank, breeding trap of size... At least a gallon... RMF>

Re: Pregnant swordtail... not reading 12/3/06
Would I need a filter? <Preferably yes. All the information you need is contained here:
http://www.wetwebmedia.com/FWSubWebIndex/fwset-up.htm Regards, Jorie>

Re: Pregnant swordtail
- 12/05/06 Okay thank you! But now all of my fry are squeezing themselves between the glass and the rock I have and killing themselves! How can I prevent this? <Eliminate the space between the glass and the rock. Jorie>
Re: Pregnant swordtail - where to give birth, raise fry, etc.
- 12/08/06 Ugh! I'm so sorry to bother you so much. My red Platy is always "sitting" (almost literally) at the bottom of the tank. I can tell she's not even close to due date. I had (HAD) flashing Christmas lights in my room. Could it be she's scared or stressed of those and is still in a little bit of shock? I don't have the flashing lights anymore because I thought they could be causing the platy to do that. Thanks, Sean <Sean, the lights may well have been confusing the fish - good decision to turn them off. Otherwise, as long as all your water chemistry is good (no ammonia, nitrites or nitrates, constant/reasonable pH, temp...) and your fish is eating, I think perhaps she may be closer to giving birth than you think (and as you know, this is common behavior for birthing females). At this point, I highly recommend a comprehensive or two on livebearers (readily available at your library, or www.amazon.com) to answer all of your detailed questions, and provide you with more information that you could dream of! Best regards, Jorie>

Swordtail info. Repro., sel., sys. 11/27/06 Hello every one, <Hey FJ! JustinN with you today> I was cruising the net looking for info on the gestation period of Swordtails when I found your site. Wow lots of info. Great site. My hats off. <Thank you, is appreciated> It's been a while since I've had a serious tropical tank. ( I got into freshwater for a long while ) I've recently set up 3 tanks for tropical fish. 1 show tank 55gal. and 2 20gal. 1 for isolation and 1 as a nursery. plus 2 more are on the way. <Sounds well thought out> Although it's been awhile I think some of your readers might like hear a couple of the basic thoughts I have on this subject and maybe they'll have less problems. <Ok, will post for all to see> 1 - Maintain your ph.. @7.0 no more no less I have found this makes for a better well rounded tank with less stress and less stress means happy fish, and happy fish ( from my observations ) means less parasites. 2 - Double the recommended amount of salt in your system.. the fish don't mind but the parasites do. 3 - Never let the water temp drop below 78f I find 78-->80 degrees is perfect (for happy fish) 4 - Quarantine your plant for awhile just as you would your fish...before putting them into your main show and/or stable tanks. 5 - If possible feed your fish more than once a day. I like to do this when I have breakfast & dinner. Never feed just before you turn off the light. 6 - Frequent water changes pulling 50% of the water out of the system every 3 months and changing you filter carbon and floss every month (and cleaning the filter itself) 7 - Minimal decorative gravel on the bottom of the tank (less the better) 8 - Know before hand how certain fish will interact with others. 9 - Have a diversity of life in the tank, fish ,snails, crayfish, frogs, plants, well you get the idea. <Not too keen on the idea of crayfish with fish here, but I digress> 10 - Last but not least a nursery tank should be jammed with plants and snails. I know this is all stuff you already know but maybe you could put it in your own words and let the people know. My wife thinks I'm crazy ...and she's probably right, but happy fish can make you happy. Thank you for your time. FJ. <Thank you for your suggestions. We will post for all to see/read. -JustinN>

Pregnant swordtail 11/20/06 Hey I have a pregnant swordtail. I cant tell when she's due but I need to know something: The person at the pet store said that usually they will have there babies right when they change environments? is this true? <Sometimes, yes... due to the added stress. Not altogether a positive thing however. Often many of the young are still-born> And he said if they haven't had them within a day or so of getting them they will probably die with all the babies in the stomach. is this true also? Sean <Can happen... though most often not... Depends on many factors such as "how close" to parturition the mother is. Bob Fenner>
Re: Pregnant swordtail 11/28/06
Okay so my swordtail had babies...but about half of them (about 15) came out still in the little "egg" that they are supposed to grow out of in the mom's stomach. What happened here? <Pre-mature... the mother perhaps stressed...> I now also have a pregnant red platy. But I cant tell when those little eyes appear because she's a red platy and I cant see through her too well. I do see the gravid spot though. Will I eventually see the eyes or is the red too dark to be able to see them? <Perhaps either> If she is too dark, how will I know when about she's do? Thx for the help last question hope you can help me again! <Only time, experience/observation can tell here. Bob Fenner>
Re: Pregnant swordtail 11/29/06
Thx! and is a 3 inch by 3 inch base, and 4 inch height (with V inserted) too small of a breeder to have swordtails or platies in? <Yes... too small... should be at least twice these dimensions> and because I had the swordtail in there could that have mad her have premature babies? <You are correct here. Bob Fenner>

Swordtail fry 11/6/06 My swordtail fish just had 12 babies and I was wondering how long does it take for her to get pregnant again after this batch? <Can happen almost immediately afterwards...> How long do I have to keep the babies out of the main tank ? <Is your concern having other fish eat the fry? This depends on what other fish/livestock you have - so long as the fry are large enough to evade the mouths of other fish, they can safely be moved into the main tank. And, if you have adequate cover (decor, plants, etc.) in the main tank, you can even let the fry grow in the main tank. What type of set-up do you have for your main tank, and your fry? Do keep in mind that fry are very sensitive to poor water conditions and need regular water changes, along with specialized food (something like Hikari's First Bites)...raising fry is a lot of work, but can be very rewarding. As cute as they are, do make sure you have room for the adults...otherwise best to let nature takes its course and feed the larger fish, IMO. Jorie>

Marigold Swordtail Fry 11/4/06 Hello, <Hi!> I have a 36 gallon tank 4 panda Corys (no idea of sexes) and 4 Marigold Swords, 3 females and 1 male, that were just added to the tank about a week and a half ago. <Hopefully you quarantined the new fish for a few weeks prior to this...be aware that many fish are carrying/harboring nasty diseases when they are first purchased, and can very easily wipe out an entire established aquarium...> I knew the one female was pregnant... <Not surprising with livebearers! They seem to be almost *always* pregnant...> ...but did not know how long it would be until she gave birth. <Gestation period is about 4-6 weeks...> I do not have a maternity tank or the time to get one cycled to the exact balance of the main tank, so I purchased a breeding box and put it in the main tank. However, afraid to stress out the mother to be (those boxes are so darn small and she was so huge) I missed the birth (Nov 1st) and the babies are in the main tank. <I think you made a good choice - I personally am not a fan of those breeding boxes, as they do tend to stress the mom out. That's about the worst thing you can do to a pregnant fish...good call on your part.> They are pretty clever about hiding in the grass, coral, plants, trees, (all fake) between the breeding box and glass, and in the gravel. <Survival of the fittest at work indeed! If you only have the swordtails and Corys in the tank, I think the majority of fry will be fine. I know there's some evidence of livebearers eating their own young, but I have never personally witnessed it...> Mom seems to be doing okay, she's swimming around much more today - although she has a little chunk of her tail missing. <Perhaps a bit of aggression from one of the males? Keep an eye on her, and do keep the water conditions very good - you don't want a secondary infection to begin at the wound site...> I did a chemical reading on 10/31 and all levels were great. Ph 7.0, Nitrates 20ppm, Nitrites 0, ammonia 0, temp averages 75F. <Nitrates at 20ppm is the very high end of OK...I'd suggest a partial water change. Nitrites and ammonia are obviously good! Also, with regard to temperature, what do you mean by "average", exactly...keep in mind that stability is very important - you don't want large temperature swings, as this will compromise the fishes' immune systems...> I have been feeding Wardley Flakes, small portions more often... <Very good.> ...trying to occupy the grownups while trying to feed the fry the baby food - Spectrum small fish formula (I have the grass on one side of the tank only). I put my hand down into the tank and try to sprinkle the fry food over the grass. <Do the fry actually eat that food? It may still be too big. I've got the same stuff (Spectrum New Life small fish formula), which I feed to my guppies, but I use Hikari's "First Bites" for my molly fry for a couple of months...their little mouths are quite tiny!> Okay, now that I've given you all the info I think you might need... here are my questions... 1. How often should I be feeding the fry? <A few times per day.> The adults and Corys? <Once or twice per day. I feed all my fish just once a day, in the evenings, but twice is OK, so long as its done in small amounts...> 2. Should I keep the fry in the main tank? (I'm sure you are laughing at this one thinking, "Yeah, like you're ever going to be able to catch them to get them out of there.") <Hee hee - with regard to catching them, I use a turkey baster to suck them up...and usually end up destroying the tank in the process! But I think they should be just fine in the main tank. Do keep the water quality up, though, as fry are even more sensitive to toxins than are their parents...> 3. Should I be doing water changes? If so, how often and how much? <Absolutely. Presuming the tank is cycled and you don't overfeed, I'd say 5 gal. every week is a reasonable schedule. You can always check the levels with your test kit and do more changes if necessary...I don't think it should be.> I can't try to vacuum the gravel now because I may get the fry, right? <The fry, as you've noticed, are pretty resourceful and quick. I use a siphon to do water changes on my fry tank, and in the event I accidentally suck one up into the 5 gal. water change bucket, I just put him/per right back in the main tank...no harm done!> 4. Will the Corys eat the fry as well? <I don't think so...never been a problem in my community tank.> 5. Will my filter suck up the fry? <It's possible. Every now and again I lose a fry like this.> Should I put something over the intake? <You can use a bit of pantyhose and a rubber band to cover the filter, I'm told...> It's an Aqua Clear Power Filter for up to 70 gallons. <Excellent filtration - I like to use more than recommended on my tanks as well.> I don't know how many were born. I really can't give you a definite count of how many there are today maybe 6, maybe more, it's hard to see them. <I understand!> I appreciate any and all help!! My husband and I are going away this coming week and I have to instruct someone else on what to do, so I want to be sure I'm giving all my of my fish the best care possible. <When my boyfriend and I travel, we make little plastic baggies containing each portion of food for the "fish-sitter"...it's a pain, but makes life easier for everyone, and reduces the risk of overfeeding. How long are you going away for? If less than a week, perhaps do a larger water change right before going (10 gal. perhaps) and don't bother to have the person watching the fish do anything...if longer than a week, well then I would suggest requesting a water change.> Appreciatively, Mary <Good luck, enjoy your fish babies, as well as your vacation! Jorie>
Re: Marigold Swordtail Fry
11/5/06 Thank you so very much Jorie!!! <You're welcome!> I did a water change tonight and very carefully siphoned the gravel - and yes every body steered clear - even the fry!!. I changed out about 4 to 5 gallons. (I made a mistake when I told you that the "Nitrates" were at about 20ppm - that was the "Nitrite" reading - the "Nitrates" are at 0.) This evening the Nitrites had risen to 50ppm so I figured that I had better fix that immediately. <Yes...nitrites and ammonia NEED to be at zero; as mentioned previously, 20 ppm for nitrates is at the high-end of acceptable. I'd suggest doing another test after this water change...make sure parameters are now good.> When I said the temp "averages at 75F - it was because we have a heater in the tank and it is set at 75F. The temperature only varies a few tenths of a degree. <That's just fine.> I am now worried about the mom, she seems to be hiding again. She did come out and eat this evening, but she is hanging out at the bottom of the tank hiding in the back and under plants and looks pretty lethargic. She also has a tiny white dot on her side. It's very hard to get a good look at it with her staying hidden, but it seems to move (like a scale that has come loose but is clear). I had read on another site that mom's very often die after giving birth - I do not want to lose this fish. Poor thing has had a rough time of it and shouldn't have to suffer. I am trying to keep a very close watch on her. <Good idea - also, make sure to keep up on the water changes. The readings you listed before were too toxic to the fish, and this could likely be causing her behavior. Do keep an eye on the "spot" - keeping the water pristine will likely address the problem, but obviously if things get worse, you'll have to re-assess. This is yet another reason to keep the water very clean, as you don't want a secondary infection to set in...> I have not actually seen the fry eat anything. I tried to crush some of the flakes tonight and sprinkle that over the grass, but a lot of it floated to the middle and top of the tank. I will purchase the other food (Hikari's First Bites) tomorrow. <The crushed flake should be fine for them. I wouldn't worry too much about not physically seeing the fry eat...they have to be crafty and hide in order to survive, so they likely eat when no one (you and other fish!) are watching. See if you can tell if they are excreting feces...that always indicates that they are eating something...> Jorie, thank you again for all of your time and wisdom. God Bless you!! I hope you have an extremely enjoyable weekend!! <And you also, Mary! Keep up on those water changes and I think everything should be A-OK!> Sincerely, Mary <Regards, Jorie>

Xiphophorus on the menu - 11/02/06 Hi everyone, I have a couple of quick question to ask you guys about sword fish. I plan on keeping the swords for two reasons there looks and for the fry that they produce to be eatin by my two angels and rainbows. My first question is can different species of sword fish be kept together. <Yes> Second what should the male to female ratio be. <One male to two or three or so females> Third how many sword can I keep in a 45 gallon tank with two angels, two rainbows, and 6 Corys. Thanks --Sbatiste <Mmm... a trio or two. Bob Fenner>

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 isnt 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 <<Youre welcome, Amanda. I hope all goes well. Tom>>

Swordtail Reproduction - Gestation Period 10/10/06 Dear Crew, I have two black female swordtails. There used to be a male but he died of an unknown cause. <More times than not, the cause may be unknown but not undeterminable...have you recently tested your water parameters (ammonia, nitrite, nitrate, pH, etc.? Do try to figure out what happened so you don't lose any more...> I want to know how I can tell if the two females are pregnant. I have tried to look for a gravid spot, but they are black so if it's there I can't see it. <Understandable.> I have also tried to see if they have gotten any fatter, with no luck. <Over what period of time? Gestation period is 4-6 weeks...if these females were kept with the male for any period of time, or were recently acquired from a LFS where they were kept in a community tank, they are likely pregnant - give them some time to develop and you'll likely see fry!> Thank you, for your time. <You're welcome. Jorie> Sincerely, D.Throne

Swordtail breeding 7/15/06 Hi, I was wondering about some things. First, I have 6 swordtails (2 male, 4 female), three rasboras of some sort (small), three black tetras, two bronze Corys, a Pleco, and a Betta (in a 29 gallon tank). I started with two (male/female) blue mystic swordtails and an orange and black female. The male seemed to take no interest in the orange one. The blue mystic female also looked pregnant. It has been over a month and she hasn't given birth yet. So then I got a pair of neon swordtails and a really big red and black one (biggest in the tank). The red and black one doesn't have a gravid spot and the neon female does but isn't fat. She is the smallest swordtail in the tank. Both the Neons are getting chased by the first male. I took the first male out (put him in a breeder net thingy) for a few hours to see what would happen. The neon male wanted to mate only with the blue mystic swordtail. My overall goal was to have a somewhat community tank and have lots of baby swordtails. My dad had swordtails when he was young and his reproduced very often, <Today... things are different> but only one of mine seems to look the slightest bit pregnant (the blue mystic), and she is somewhat fat. Do swordtails cross-breed, or do they fall in love with just one other swordtail? <Do crossbreed... all Xiphophorus helleri... even with platies...> Or am I doing anything wrong? <Likely nothing... Many livebearers are "modified" with the use of steroids/hormones... to change their apparent (phenotypic) sex... And many are otherwise sterile from techniques utilized during their raising. There are still good breeders/suppliers from Florida (e.g. Ekkwill), and a few "local" breeders about if the stores near them are lucky... Only time/patience, good care, nutrition will tell whether yours can/will reproduce. Bob Fenner>

Swordtail Sex Query 7/12/06 This is a really quick question. I am pretty sure I know the answer though. I bought 2 pineapple swordtails from my local pet store. They both looked like females since none of them had the sword. Now one of them is either turning into a male, or he is just maturing because he is growing a sword. <Maturing.> Can they change sex? <Not that I'm aware of.><<Actually Xiphophorus can do this... though phenotype is not always a clear indication of functional sexual capacity. RMF>> Now I think I need to buy some more females to make the amount of females higher compared to the number of males... right? <Would be best, although somewhat depends on the temperament of the individual fish.> One more thing, can the other females be a different type, or do they have to be pineapples to keep him from chasing only one female? <Usually any other female swords will do, although some males are choosey.> Thanks! <Sure> Can platys and swordtails breed? <Yes> <Chris>

Swordtail/Xiphophorus Reproductive/Genetic mysteries revealed, discussed... 7/2/06 <<Hi, Jessi. Tom>> Ok, so I have been breeding my swordtails for a while now. The thing that is getting me is that the majority of the females will either have a brood and then become male or just plain out become male. <<Jessi, the ones that are "plain out" becoming male are simply "late bloomers", so to speak. Not uncommon, actually. As for the females becoming male, you've made a highly interesting and, highly unusual, observation. According to Philip Hastings of the Scripps Oceanographic Institute in California, the sex of Swordtails is determined genetically through their chromosome makeup whereas there is no special DNA difference in fish that are known to change sex "naturally". There have been extremely rare instances of hermaphroditic occurrences with Swordtails but for these to be "frequent", like in your case, would be almost out of the realm of possibility. One thing that does strike me as more plausible is that older females may develop what appears to be a gonopodium (the "sword"). This is more of a physiological transformation than a reproductive one since these fish are nearly invariably infertile though it's not unknown that they may actually try to mate with other females. Of course, Swordtails would try to mate with a French Poodle, given the chance. :)>> <Note: the "sword" is usually the term given to the extended rays on the tail, not the gonopodium/modified anal fin. -SCF> This is leaving me with almost all of my swordtails being male. I am afraid of this situation because, though they have not become aggressive towards each other yet, over the few remaining females, I fear they may. Is there any way, such as water conditions, that I can stop this from happening so often or will they just do it as their instincts see fit? <<I think you're going to have to "go with the flow" here, Jessi. As I said, yours is an interesting situation based on my knowledge of these fish. As you're aware, though, these animals will breed in practically any habitable water conditions so the chances of changing these to reduce/eliminate what seems to be going on is remote.>> Thanks for the help. Jessi <<Don't know that I've "helped" but yours was an interesting post. Tom>>

Swordtail pregnancy 06/14/2006 Hi Bob <Not Bob tonight...Jorie here. Hello!> Last night I put my pregnant swordtail in a hatchery that floats in the aquarium, she kept jumping out. This morning got up she had babies in the hatchery, but she had jumped out in the big tank and she also had babies in there. She still looks pregnant do you think she was done delivering. Now my male swordtail is constantly chasing her. What should I do? <How big is the main tank? Are you planning on raising the fry - do you have room for them? If not, best to let nature take its course and let the births happen in the main tank. With regards to the mom - she really doesn't want to be in that breeder it looks like...as long as you have ample space and hiding places in the main tank for her, she should be OK. If you keep putting her back into the breeder and she keeps jumping out, she's going to injure herself, so I wouldn't suggest that. A little more info. on your tank setup would be helpful, here, but presuming you have an appropriate setup, there shouldn't be any harm in allowing her back into the main area.> Thank You <Hope I've helped...Jorie.>
Swordtail pregnancy PART 2
06/14/2006 Hi Jorie <Well hello again!> I have a 30 gallon tank, It's a community tank with 2 Colombian sharks, 6 Danios, 2 swordtails, 1 red tail shark, 1rainbowshark, 1algea eater. <Well, the Columbian sharks can reach an adult length of up to two feet, so I hope you've got a large aquarium to move them to! Also, it is my understanding these fish are freshwater when juvies, but are truly brackish when mature. With regards to the other "sharks", it is my understanding that the common names "redtail" and "rainbow" both refer to the same fish, Epalzeorhynchos frenatum. I would recommend that you don't keep two in the same tank, as they can show aggression towards conspecifics. Depending upon what type of danios you have, I'd say find a more suitable home for the Columbian sharks, ditch one of the redtail/rainbows, and add some more swordtails, to increase the amount of females to male. If you've just got the one boy and one girl, she's apt to be picked on a fair amount. Usually with livebearers, space permitting, you want to keep a 1:4 male:female ratio or so.> I vacuumed my tank every 2 weeks and add water and aquarium salt - my water is always crystal clear. <What about water changes? You should be doing a weekly 50% change or so, as you are pretty fully stocked...> My female sword tail is in a 2 gallon tank recuperating from the pregnancy. <Got it. She should be just fine swimming around the 2 gal. for a while. Give her a week or so to rest up and recuperate.> After I put the female back in the main tank can the fry go in the 2 gallon tank or how long can they be kept in the breeder. <You can release the fry into the 2 gal. as soon as you like - in fact, I have never personally witnessed a livebearer eat her own fry, though I've read it can happen. Seems as though you are planning on keeping the little ones...how many do you have? Once you are able to sex them, you can use the bigger ones to add more females to your main tank, as mentioned above! With livebearers, you won't believe how often they reproduce - at some point, you'll be swimming in swordtails (pun intended!) Once that becomes the case, you can always just allow the females to give birth in the main tank, and I'm sure your larger fish would be very grateful for the live food source...> If you would like to see a picture of my tank just ask and I'll send you one. <I always like seeing others' tanks - send away!> P.S Do you have a personal e-mail <address> so when I send something it reaches you? <I do have a personal e-mail, but you'll forgive me if I don't want it to become inundated with fish queries. You can always reach me here, and if you want to make it extra-easy for folks I share this in-box with to identify, you can just put "Attn: Jorie" in the subject line, or something similar. Take care, Jorie>

Swordtail Delivery Duration - 06/07/06 Hi All! What a great site with helpful and insightful information! <Thanks> I have searched your site (and a whole lot of others!) and can not find an answer to the following question. How long is the duration of fry delivery for swordtails? Or asked another way; what is the expected time between the births of the first fry until I should expect the last? <A few hours to a day or so> I have a female swordtail in a separate 5 gallon tank (bought specifically for this purpose) that has given birth, however, I can only find 2 fry in the plants and her gravid spot is still clearly dark. <Mmm, might be a "small batch"... or could be hiding still... or eaten> I noticed the first fry last night and decided to wait until this morning to move her back to my main tank. However, when I checked this morning, nothing had changed. There were still only 2 (findable) fry, and her gravid spot still appears dark. <Sometimes the vent area does continue to look thus for a while> As a side note, I have a guppy that gave birth to 13 fry about three weeks ago in a breeder box in my main tank (29 gallon). All 13 are healthy and growing rapidly. I am hoping to move the female swordtail from the 5 gallon back to my main tank, and then move the 13 guppy fry into the 5 gallon with the new swordtail fry. They are all small enough that they can't eat each other, and this would be a safe place for them until they get big enough for some to be introduced back to the main tank and the remainder sold to my LFS ( I checked this with my LFS first!). <All good> Figuring between 21 and 28 days gestation, the guppy is due again between June 8th and 15th and I need the breeder box! :) Tank Stats for both tanks are: Nitrite = 0, Ammonia = 0, Nitrate = 5-10 ppm, PH = 7.2, and Temp = 78 deg. f Thanks for any help you can provide, and thank you for such an informative site. Dan St. Charles, Illinois <Feed frequently, small amounts, be diligent re regular water changes (even daily) and your young livebearers should grow quickly. Bob Fenner> Swordless Swordtail - 5/7/2006 Hello, well I got 2 swordtails 2 days ago and 1 is fat and 1 is thin. I think I have 1 male and 1 female, but the male doesn't have a sword yet. Is it a male? If so when will he get his sword? Many Thanks Stu < In a dealers tank only one male swordtail will have a really long sword. They may be very short or entirely missing on the rest. When the dominant male swordtail is taken out another one becomes dominant and his tail begins to grow large. Look at the anal fin to be sure. The male's anal fin has been modified into a tube to penetrate the female.-Chuck> Swordtail labor - 04/19/06 I have a female swordtail, whitish in color, I believe it is a neon swordtail. This morning I noticed a baby in the tank, we put her and the baby in the "V" shaped breeding trap. I was wondering how long will she be in labor, <Likely less than a day total> I don't know if she has already had all the babies and this is the only one that survived, or if she is still going to have more. She does still appear to be breathing rapidly. How quickly do they eat the fry, how many at a time will they eat, etc.? <Can eat all in a short while, or none at all... or in-between> We are new to fish parents having only had our tank about a month. Thanks for the help! Dana <Please read here: http://wetwebmedia.com/FWSubWebIndex/swordreprofaqs.htm and the linked files above. Bob Fenner>

Pregnant swordtail not eating 2/22/06 Hello, <Hi there> Could you tell me if it is normal for a pregnant marigold swordtail to not be eating? <Often do stop feeding...> She was eating voraciously and then 2 days ago she started hiding from the other fish. Today she is hovering near the top 1/4 of the 55 gallon and has not eaten today or yesterday. It appears her pregnancy is in the final stages, so I expect them to drop within the day. Is this behavior or normal in her current state? Thank you! <Is not atypical. Not to worry. Bob Fenner> Judy Stout

Swordtails Without the Sword 2/18/06 I have 3 female high fin Swordtails, recently purchased. One of them seems to be a bit more aggressive, and it looks like she has some extra equipment on the under side (similar to my male Molly but not that developed), but she doesn't have the long sword tail that I associate with this breed. I've read arguments either way saying the Swordtails will change gender in the absence of a male, but I wasn't sure if this was what was happening. Please don't post my email address on the website. Also, if possible could you respond via email? I don't always have access to the external internet to view the site but my email should work. Zach < Not all male swordtails develop long tails. Sometimes it is in the genes or may have been bitten and fungused off.-Chuck>

Dying Sword Fry (Sorry if I just sent you the beginning of an email. I had an 18 month old helping...lol.) OK, lets try this again. I have 1 male and 1 female red velvet swordtails. (along with mollies, platies, barbs, killies, danios and 1 albino rainbow shark) I've had the tank (33g) up and running for about 3 months. The female swordtail had babies about 3 weeks after we got the pair. I separated the mom after seeing her give birth to a few fry. She had 6 more in the v-breeder (one of which she ate before it dropped to safety). That left us with 5 adorable little ones. Anyway, They were all fine for a few weeks in the v-breeder. Mom had been moved back to the community and the (v) had been removed from the breeder. I didn't feel there was enough water flow in the breeder so I purchased a net breeder and placed the fry in that. After about 2/3 weeks 2 fry died within a couple days of each other. They were approx. 5-6 weeks old at the time and seemed happy and healthy. Then everything seemed fine for a couple of weeks. As of last week, at approx 8/9 weeks of age, I've lost 2 more a day apart from each other. I'm left with one lonely little baby. What could be going on? <Perhaps "just" weak young... the first few batches often have trouble> I'm feeding finely ground flakes. I don't want my last one to die but I don't know what happened to the others. I also have found stray fry swimming around my tank and have put them in other breeders and don't want them to meet the same fate. They aren't swordtails though. They seem to be 4 platies and 1 Dalmatian molly. Can you help save my babies? Thanks so much! Kristy <Be careful re moving too-pregnant females... do make just small (ten percent or so) water changes in the fry tank... and keep otherwise doing what you are and you'll be fine. Bob Fenner>

Swordtails - 11/04/2005 First of all I would like to thank you for all the information that you have provided. <And thank you for the thanks!> My first question is, how can you tell what kind of swordtail? <Umm, as in, what species? Or what "color"? There are a number of different species.... Xiphophorus helleri is the one most common in the hobby, and is available in many different colors.> And does it matter for mating purposes? <Mm, most/all the species can hybridize (though I don't recommend it), but of X. helleri, breeding different color fish is no problem at all.> I have a male that has a green line on his side that extends into the sword on his tail. He has been in my tank for 3 weeks now. The 2 females I purchased at the same time have both died. One died within a week (about 3 days), which the store replaced free of charge, a week later the replacement died. 2 weeks after the original purchase the second original female died. I have a 10 gallon tank, which I cycled using ammonia, my ammonia and nitrite levels are 0. I have to purchase a nitrate test kit, but am assuming that the levels cannot be too high, as my male and about 15 babies (which I presume are from the longer lived original female) and my flying fox are all fine. Two days ago I purchased 2 new females (my male was looking very glum and not eating, he had been alone for 4 days). One of those died overnight, and I have my free replacement. I have a completely orange female and a white female with black fins (this is the replacement and she is missing a huge piece of her tail fin, like something took a bite from her). <Again, color is irrelevant; they will likely breed. I would be concerned about the damage on the tail of the new female, however.> My second question is: Is it normal to lose so many fish? <Normal? No. I would urge you to have caution in selecting new or replacement fish; please read here for more about health in fish: http://www.wetwebmedia.com/FWSubWebIndex/fwdis3setsfactors.htm. Selecting healthy fish to begin with is of great importance.> I always hear people say they know nothing about fish, and their tank has been going for 4 years! I just seem to kill them off. <There are always reasons.... the initial health of the fish you select, the "health" of your system (water quality, etc.).... Fish, like other organisms, don't "just die".... It's all a matter of isolating the cause and fixing it. In your case, as I said, I suspect the initial health of these fish was questionable to begin with. You might want to consider getting/using a quarantine system for new livestock.> I live in the country, about half an hour from the pet store, and wonder if it is too much stress for them. <Mm, no.... Fish can and do go several hours bagged at times.... keeping the amount of time from the store to home at a minimum is a good idea, though, and never leave them in a car where they might heat or chill.... basically, do your errands first, go to the fish store as the last stop on the way home - you should be fine.> My third question is: When I got the replacement for the first female that died, the male showed absolutely no interest in her, even though the other female was obviously pregnant (she had the black spot, which disappeared after the babies appeared). Could the male have exhausted that second female, because he sensed that the replacement female was not well? She never did much and her dorsal fin was always clamped close to her back. <Again.... I really suspect poor health in these fish to begin with.> My fourth question: When should I give up, <?? Only you can decide this.> what if my females die again? <Find out why. Select only the most active, healthy fish you can find. Never purchase fish from a tank with others that are obviously ill.> How long do I persevere? <Uhh, again, the ball's in your court on this.> I reason that if the babies are surviving and growing that my water must be OK, so the problem is the fish. <I agree, to an extent.> One final note, the lady at Wal-mart... <Oh. Uh. Not to be disparaging of any store or enterprise, but I, personally, would not purchase fish from a department store.... find a fish store that is dedicated mostly or only to fish; you wouldn't buy bread from an oil refinery, would you?> ...recommended that I use QuICK cure to treat all the fish when I added these new females, just in case the other females were sick. <I would not. Medicating without knowing specifically what, if anything, you're treating is one of the many routes to disaster....> I have done that 1 day now. The instructions do not say how long to use it, what do you recommend? <I would stop using this now, unless you really have reason to believe these fish have a communicable parasite.> Sorry this is so long. <No worries.> I am grateful for any help, this is my second attempt at a fish tank. The initial attempt was with goldfish, I managed to kill 8 goldfish and 1 pleco that time! <Goldfish are much more demanding of space than most folks realize.... Much is archived on our site, in articles and FAQs, about proper care of goldfish - do please take a look if you're interested.> I was completely unaware of test kits and cycling, etc. So I was somewhat shocked when I started killing fish again after all my attempts to do things properly this time! <Begin reading, learning about fish health. You'll do fine, no worries.> Thank you, -Olivia <Wishing you well, -Sabrina>

Question on Swordtails... breeding mostly 1/4/06 Hi, I have had my tank set up for about 6 months now, In the beginning we had 3 swordtails, 2 females, (we thought), <Mmm, these can "change" sex> and 1 male... the male died about a week after we got him, and then a month or so later the smaller of the two females developed the swordtail of a male and the modified anal fin.... my female swordtail is a lot bigger then my male, but in all the months they have been in the tank, they have not bred ever... <Where are the spaces between your sentences?> as I watch the male chases the female, but she always gets away from him...could this be a false male?? <Yes, possibly> or is it part of the mating ritual??...and what can I do to help them breed... <Mmm, get another "certain" male... with a gonopodium> Also I have a Balloon Molly who had babies recently, we noticed the yellow/ black spotted babies swimming around on Christmas eve... how long before we start seeing more baby mollies swimming around?? <A couple of months> also, there are 12 baby mollies along with 3 adult fish in a twenty gallon tank, i know this is going to be over crowded really soon, what size tank should i get to raise the fry in??...thank you, Stacy <The bigger the better... maybe keep an eye out for "used tanks" in the papers, ads... as you will need/want a few tanks if you intend to raise, possibly sell the young. Please use your grammar, spellcheckers before sending out email... Ignorance is not bliss, and neither of us wants to look ignorant. Bob Fenner>

Two Questions. Swordtail ID, Repro. 1/10/06 Hello I sent an email to you guys the other day, but I think my picture was to big. So I decided to try with a smaller pic. If I need to resize it again please let me know. Hope I didn't cause any problems. I bought this fish about a month ago from a pet store. They told me it was a female Sailfin Molly. <Mmm, looks like a female "green/wild-type" swordtail to me (Xiphophorus hellerii) http://fishbase.sinica.edu.tw/Summary/speciesSummary.php?ID=3231&genusname=Xiphophorus&speciesname=hellerii> She is about three inches long, and as you can see not very colorful, but that is o.k. She looks like a large Green Swordtail, to me. Do you guys know what species she might be? <Oh yes> I also have another question, if that is alright. She looks like she is gravid, but has looked like that since the day I got her. Which as I stated earlier, was a month ago. I have been told that the eggs may not have been fertilized, that she reabsorbed them. If this is true wouldn't she have gotten thinner and the gravid spot gone away? <Yes, likely> <Welcome. Bob Fenner>


Swordtail Repro. mostly 1/10/06 Question 1: My daughter has 1 male swordtail and three females ( just got them) in a 10g tank. Today she thinks the females belly is slightly swollen ( not sure) . How long is the cycle before they have babies.. <Most... every six to eight weeks> appx. 24 hrs. having fish in tank my daughter put the suspected female in a breeder pin. Please give your opinion on this? <Is a good idea> Question 2: Can you tell us for a ten gallon tank what water test we should do and levels... <... is posted on WWM... can be a rather large topic. Once the system is biologically cycled, testing pH, nitrate occasionally... along with regular/frequent partial water changes is about all that is suggested> my wife said the pet store did about 5 and she didn't ask them what they where but they said the levels where good. <They likely included ammonia, nitrite and alkalinity> We are using tap water that is going through a water softener and a tap water purifier. Also we use a tank conditioner solution and a Bacteria solution to stabilize the water.. and adjusted the temp around 76-78 degrees. Also by the stores recommendation we increase the 10g tank water fall pump too 20g pump and also complemented it with an undergravel filter system Thanks .. <Please see WWM re these general issues... and please use your spelling and grammar checkers... Bob Fenner>

Swordtail and her babies <Ananda here answering the freshwater fish questions today...> Hello I have a green sword tail who just delivered babies I am not sure if she is done but babies and mother are doing well I have them in a separate small tank. My question is how long should I keep the mother in the tank with them. I do have breeding grass in the tank and she doesn't seem to be going after them. But I would like to put her back with the other fish. Any help would be appreciated. Thank You, Marlin <I like to keep the new mothers away from the rest of the fish for a little while. You've done that, so she could go back in the main tank any time. --Ananda>

Pregnant Swordfish I have 2 female and 1 male swordfishes. Both of my females are pregnant. One of my female swordtails are almost due to have her babies (maybe in a couple of days). I was just wondering, is there anyway I can make her deliver the fry any earlier without a problem. <Not really, you should let nature take its course here.> My water temperature is about 80 F and 27 C. My PH level is about 7.6.And one more question: all of them has Ich (I've been treating it for two days now) will that stop my pregnant female from having her babies sooner? <The Ich is my main concern here, if cured the platies will spawn again in the future, if not cured they will die. Ich is usually brought on by environmental stressors, temperature changes, poor water quality, poor diet, etc. I would focus on getting rid of the Ich, and trying to identify anything that may have caused the outbreak. Please read the article at the link below. http://www.wetwebmedia.com/AqBizSubWebIndex/fishdisho.htm Thanks. Please reply soon as possible because I am going out of town. <Best of luck, and have a safe trip. -Gage>

My female swordtail, Baby Story? I had a question about my female swordtail. The guy at the store said she was def. pregnant well I put her in a separate tank, from the others now all she does is lie on the bottom like she is dead. I have tried poking her to make her move but she just lays there she is very fat and has the black spot like she is pregnant can you help me out or not? Thank you, Kerri <Well, Kerri- It is normal for a fish in late pregnancy to have some difficulty in moving. However, if she is not moving at all, it can be a bad sign. Ask yourself a few questions. First, is she breathing rapidly? Does she have any outward signs of disease? Scales standing out, obvious marks on her body, etc? How are the water conditions in the 'maternity ward?" If they are dramatically different than your main tank, this could be a form of shock. How long has she been immobile? Don't panic, but ask yourself these questions, and be prepared to take action if needed, such as water changes. Keep an eye on her. Hopefully, by the time you get this, she'll be a new mom! Let us know if you have any more problems. Hang in there! Scott F.>

Pineapple swordtail I just bought a pineapple swordtail fish and her belly is large and we can see what we think is eyes or little black dots. We have her in a breeding tank right now and we are wondering how long it usually takes for them to have their babies. We also have another female that we believe is pregnant and we don't really know if she is or not her belly is large but it is black. If you can answer these two questions ASAP that would be great thanks. <Both of them are probably pregnant. The gestation period should be about 30 days. You're welcome! Ronni>

To Breed or Not to Breed Hello there. <Hey> I have 2 female and 1 male swords. My question is do I need the male? <Not really.> Both females have already had fry and I'm not in any hurry to have anymore. I only have a 20 gallon and 40 babies. Way too many for me to take proper care of. I'm a beginner. Thank you. <Your local fish store will probably take the extra babies off your hands. If you do not want more babies I would separate the males and the females, babies too, they will not take long to grow up. -Gage>

Swordtail Breeding >Hi, if I put a pregnant swordtail in a ten gallon breeding tank just like normal with only rocks in the bottom and the filter and heater, could you walk me through her having the babies what kind of plants I will need or peat moss like we talked earlier about and if I need a breeding net or a tank divider and everything else I should know? thank you sooooo much! >>Sure, Loyd, I'll do my best, although you'll soon discover that these things are far too much like rabbits and lemmings in their breeding propensities! Set up the little tank, you can use the plastic grass as I've mentioned to let the babies hide, or you can get a special container with a v-shaped bottom that lets the babies drop to the bottom and out of mother's reach. Filtration is best kept at its simplest, I like a basic old-fashioned air-driven sponge filter. Set it up in the main tank first so it becomes inhabited with nitrifying bacteria, and once it's really going it can also provide food to the babies. They can also be fed a special "fish baby food" that you can find at most shops quite easily, or you can finely grind regular flake food. Be careful to cull, or you'll end up with FAR more than you'll know what to do with! Have fun! Marina

Deformed Swordtail Fry (12/21/2003) Dear crew, My female swordtail gave birth in a breeding trap but some of them got out and eaten. Now I have 7 left. 3 of them are swimming normally but the other 4 have crooked backs (crooked in the shapes of 'L', 'S' and 'Z') but are still alive. They swim on their heads spirally. I've waited for them to hopefully change since 10.30am until now (5.30pm) but they're still crooked. Is it a deformity? <Sure sounds like a birth defect to me. My LFS recently told me that the quality of FW livebearers seems to be going down due to diminished genetic diversity. More defects. I've heard/read the same about angels. Some livebearers are even intentionally bred for abnormal shapes (bulging bellies & bent spines. I've seen these at Petco. IMO it's wrong to deliberately breed fish to have these abnormal, often disabling shapes.> Will they live? <Hard to say. Their deformities are obviously making it hard for them to get around. Yet if they can manage to eat, they may live/thrive. Let us know how it goes.> Please e-mail me an answer at XXXX@XXXXXXXX Thank you so much. <Hope this helps, Steve Allen>

Swordtail Abortion A Big hello from Australia to everyone... And thank you for taking the time to read this. I have been reading your site and searching for a reason as to why my pregnant Lyretail Swordtail aborted her pregnancy 2 days after being put in the breeding trap. We have a breeding trap designed to hold 2 females about 6" long and into this 2 days ago we put the two pregnant Swordtails, 1 pineapple and one Lyretail. We come home today to find the female Lyretail a lot thinner and about 50 eggs on the bottom of the breeding trap with 1 live healthy baby and 1 not so healthy looking baby, which still has the yolk of it's egg attached. I have head of Platy's aborting their pregnancy, but not Swords... As I'm really eager to breed the pair of lyre tails, could you please shed some light on this? Thanking you in Advance. Justin >>Dear Justin; My guess would be stress. Many animals will prematurely abort when highly stressed. I recommend testing your water (which is always the first thing to do) for ammonia, nitrite, and nitrates. Your ammonia and nitrite should be 0, nitrate should be kept low, around 30-60ppm is a good level. If the tank is a relatively new set-up, or if you have over-cleaned your filtration, you may be experiencing an ammonia/nitrite spike. How often do you do partial water changes? Also, next time you could try using one trap per female.. -Gwen<<

Swords without Tails My pregnant swordtail has been in the floating breeding trap for a week (she had been pregnant for 4-5 weeks prior to this). <A little long> She seemed quite happy in there and not unduly distressed. However tonight I noticed about 50 dead fry on the bottom of the tank. Most you cannot see a tail on them so I can only presume are malformed. Water quality is ok on testing, what have I done wrong we have no live fry !! Please help Gill Smith <First, please post the numbers from any testing. All I have to go on is waters ok, 50 dead fry, and no tails on most, but I assume not all. Could be caused by stress, water quality (ph, hardness, salt level etc.) or be genetic in nature. If we eliminate the environmental factors of stress and water, as you seem to do, we're left with genetic. If that's the problem, mating her to a different male may help. Two problems with that. Females can use the sperm from one mating for a few batches of fry. Plus, any young from her would carry the defective gene as a recessive trait. It may pop back up in any future generations. A good breeder would not continue this bloodline. But again, there are many other reasons that may have caused her to abort. Infection is also a possible cause. Don>

Pregger Sword My swordtail is pregnant for the second time. The first time 2 fry survived and were growing happily hiding in the bushes until one day they got too brave and ventured out and presumably got eaten, as they disappeared !However she is huge again and definitely pregnant so 3 days ago we put her into a floating breeding trap where she is "sitting " quite happily but no fry yet ! How long should we hold her in there if she has not produced . Also there is nothing in the breeding trap other than water ! How long should the fry remain in there after they are born and should I be putting anything in the bottom of the trap ?? < Sometimes breeders put some plastic foliage in the bottom of the trap to attract the fry. If she looks very pregnant then I would leave her in there until she gave birth. After the fry are born they should be moved to a small aquarium of their own. Grow them up until they are too big to be eaten by the parents.-Chuck> Thank you in anticipation Gill

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.

Swordtail pregnancy Hello I'm emailing because I have a female swordtail that is pregnant, I learned this from reading others peoples questions to you and the answers you gave, I was wondering if you could email me at this address _XXXX@aol.com_ (@aol.com) telling me how long it takes for a female to give birth as my female has now been clearly pregnant for at least a month could you tell me how long it usually takes for a female swordtail to give birth from conception to delivery. <Take a look here http://www.wetwebmedia.com/FWSubWebIndex/livebearers.htm, Personally I have found that their belly starts to square off as they are about to deliver and looses that more round appearance. MacL > Thank you very much. <Good luck>

Swordtail babies hi, my name is matt, <Hi Matt, MacL here with you tonight> I'm new to aquariums, and I have some questions about my pregnant swordtail... I know nothing about breeding, my g/f just thought it would be cool to have little fish babies. I have gotten some facts from a fish expert at Wal-mart and she said that I should look for the black sac holding the babies(livebearing) to come to a point at the top. <Its more like the body squares off and they have the babies.> I thought I noticed it coming to a point, and so I put it into a breeders net and have been watching it, it looks like the sac is starting to shrink?? but I haven't seen any babies running around? <Sad to say sometimes the parents will eat the babies.> what do I look for? and how should I handle this.... I just found your website today, so do you send these answers to our e-mails?? <We send answers back to the email address and then post them later.> because I wouldn't know how to check what you wrote back?? Thanks Matt

Popping Swords how can I tell when my female swordtail fish are about to give birth < They are usually swollen in the belly region with a dark blotch towards the back half of the belly.> I only had one of them 1 day and I saw lots of little fish in the tank took me 11/2 hours to catch them so you have probably guessed I didn't see how was the 1 but the look like them and now both females are large and have dark coloured bellies it has been 3 1/2 weeks now I have put both fish in plastic breeder how long can I leave them in there for hope you can help many thanks Kristy < There is no exact science on when a female is ready to give birth. If the back half of the belly develops that dark area by the back of the belly it is usually the eyes developing from the fry so this is a sign that the birth will come soon. Put them in a breeder net and raise the temp to 80 F and you should have some results in about a week.-Chuck> 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>

(Not) Pregnant Swordtail Sorry if this has already been answered, but I have a swordtail who appears to be pregnant, and the scales are all standing out. Happened overnight - is this normal? Thanks so much, appreciate your help as always! Pat <Not normal, not pregnant... Your Sword has a condition termed "dropsy". Please put this term in the search tool on www.WetWebMedia.com and read the links. Bob Fenner>

My Swordtails About a week a go I bought 2 pregnant females and one male swordtail. <Best not to move such late pregnancy livebearers...> Right now I have the female that is closest to their do date in a 2 1/2 gallon tank. After the female gives birth, I am going to put her in a 2 gallon tank for a day, and then put her in with the other swordtails. How long do I keep the fry in the 2 1/2 gallon tank? <Mmm, until they are too large for the fishes in my main tank to eat them... with regular feeding, water changes... likely a month or two> When could I put them in with the adult fish even though there is enough cover... plants, weeds, etc.? Can you also send me an e-mail saying how to hatch Baby Brine Shrimp (the easiest way and the less messiest way). Send a couple because I have read about 20 different things on it and so I would like to pick it my self <What we have re Artemia is stored here: http://www.wetwebmedia.com/artemiafaqs.htm> Thanks Steve Young P.S.- write me back ASAP because the fish is going to have birth one day in between 1-6-05 and 1-15-05 <Ah, a new aquaculturist is born! Bob Fenner>

Feeding Swordtail Fry I have a pineapple swordtail that just gave birth. I'm pretty sure that the babies will survive for a time on their egg sacs, but what should I feed them or how soon. I only have flake food available right now, but maybe you could suggest something I can get for them that would be better... Please reply soon... Barb. <Powdered flake is a fine food for swordtail fry. You could also hatch some baby brine shrimp. Feed tiny amounts a few time a day for fry. The leftovers will be lost in the gravel and decay. You should be testing your water for spikes in ammonia. Use a gravel vac when doing water changes to keep thing clean. Young Swords will start to eat within a day or two of birth. Most of their yolk is used before birth. Congrats and good luck. Don>

Is my pineapple swordtail wag pregnant? Hey! My pineapple swordtail wag female is in a tank with one other male and a frog. They've lived together for about a month, and lately she's become extremely fat. I was reading through the other questions, and people were talking about the disease "dropsy" and they say the scales pop out, but hers don't, and she's the only one that is fat. I looked for a black spot on her belly, but she doesn't seem to have one, is she just fat or is she pregnant? <Good observations and reporting... hard to say... are you feeding something/s other than dried food? Do you have some "greenery" in the tank your fishes can chew on? It may be that your Sword is pregnant... but it might just be fat as you speculate... Best to keep an eye on her vent area... As you remark, this area will become clearer, more transparent in appearance if she is getting close to birthing... and you should be able to make out the young's eyes getting close to parturition... Bob Fenner>

Swordtail Sex Change Question I have a breeding pair (unintentionally) of Swordtails in my 55 gal tank. She is a Pineapple Sword and he is a Green Sword. <Same species...> She has had several broods where 3-4 babies would survive in the tank. So far, they all seemed to have been females. <Ahhh, this happens... by also Xiphophorus does "change" its (phenotypic/apparent) sex in time> The oldest 4 are several months old now, and I am fairly sure they all HAD babies... now TWO of these seem to be turning into males. <Oh, yes... I haven't woken up yet> The once flat anal fin is turning long & narrow and they are growing "swords" on their tails. I have read that this can happen, but does anyone know WHY? <Perhaps this allows for some of both sexes...> Did they actually have babies then change sexes? <Possibly> Could it be because there are so many females in the tank and only one (original) male? Will they be able to breed? <Yes... these are likely functional males> They are both very large, like their mother, not small and long like "dad". Thank you for any help... (My husband thinks I am crazy!) Bev C <I think you are a good observer, have a curious and good mind. Bob Fenner>

Shy Swordtail Hello! I'm new to the fish game, learning all the time - thanks in large part to your site! My question is about a female swordtail I bought a couple weeks ago. I think she's pregnant, buy my question is about how she's acting - she hides all the time! I have a large piece of coral in my tank - she spends about 80% of her time squeezed into the nooks and crannies. The few times that I've coaxed her out (at one point, I thought she might have died in the coral), she leaves the coral and goes straight into another decor item I have, and hides there! I have one other female swordtail, a male, plus several goldfish and 6 neon tetras. All the fish get along really well, except for this one shy one. Is this behavior an indication that she's pregnant? Or, is this just the way she is? Any suggestions for helping her "come out of her shell? Thanks for your help! Tom <Many females will go off by themselves when ready to drop. Both she and the fry would make an easy target for a hungry cichlid if not. Could just be a shy fish also. The more places a shy fish as to hide, the more it will come out. It will feel safer. The big problem I see is mixing tropicals and goldfish. Not good. The Neons and swords want a temp in the high 70s to low 80s. The goldfish at least ten degrees cooler. They also do better on different diets. For the long term health of these fish I suggest you return the goldfish. To keep several goldfish for life requires a tank of over 150 gallons. Don>

Fry Among the Sharks I have just got my neon swordtails 1 day ago and the female looks to be pregnant she has green looking eyes in her belly. How long is a swordtail pregnant? How many babies will she have? And how long should they be in a different tank, oh and one last thing I have a 55 gallon tank with 3 Bala sharks, 1 silvertip shark, 3 tiger barbs, 2 pink kissing Gouramis, 2 African Auratus, 1 peacock eel, 3 rainbow sharks and 2 neon swordtails, will my swordtails breed again in my large community tank? Thank you so much, I'm new to this I need help. Please write me back very soon, sorry if I have asked to many questions. Alicia. <A healthy well kept swordtail can give birth every four to six weeks. She can have just a few, or a large brood of 25 or more. They will have to be kept away from the 55 until almost full grown. The adults will breed again, but little chance of the fry making it unless removed. You have a pretty aggressive tank there. Or it will be soon. Too many big fish for a 55. Don>

Surface-dwelling Swordtails and Sexing Tetras Hello. I first want to thank you for the previous information. It was very helpful. I still have the swordtail that looks pregnant. Lately (like the last 24-36 hours) she has been staying near the surface. Does this mean something? <Livebearers have been known to hang out near the surface when they are about to drop young. Keep an eye out.> She eats and has regular bowel movements, but if she is starting to develop a disease or something, I want to catch it soon. What do you suggest I do? <Well, if she looks and acts healthy in all respects other than this abnormal behavior, I really cannot pinpoint what (if anything) is wrong with her, as hanging near the surface is a symptom for many things. I assume it may be due to her pregnancy that you mentioned, but it could be a host of other causes. Low oxygen, being bullied, disease, stress, just to name a few. I would recommend your watching her closely, and taking action if you notice anything else out of the ordinary.> All the other fish in the tank swim around. The water is fine. <When you say that the water is "fine," it is about as useless to me for determining if your water is of concern. The readings you get from your test kits are magical in that respect. Something could be wrong and you may not even know about it, and it could be hidden within the readings. Don't be afraid to send them along if you think something is wrong.> Oh, and another thing, I have a couple of tetras. How can you tell what sex they are and when they are pregnant? <Depends on the tetra :-) > I know they cannot be as easy to sex as swordtails; is there something that an amateur, like me, can see that will let me know if the fish is male or female? Thank you so very much! <Again, depends on the species. Some species are sex-able, but most are not. Check the following page for tetra species identification. http://www.wetwebmedia.com/FWSubWebIndex/CharaciformFishes.htm Hope this helps, Mike G>

Swordtail fry Hi. I just got into this fish thing and I am finding it quite enjoyable. I have had my fish for about 2 weeks now. I bought two female swordtails that were pregnant. One of them had five babies (I know she had more, but I think she ate them all.) anyways, the second one popped about 3-5 days later. She had quite a few, about 20 babies or so. She still looks pregnant, but I put her back in the main tank because I cannot handle any more. If the babes live in the main tank, fine, but if they do not that is fine, too. Anyways, my question is this. I took them out of the breeder net because there was just too many. I put them in a 1-gallon tank, no heater, but with an air stone. They are doing great. I have not lost any, well except for the one that stuck to the net and went down the drain, but oh well. I wish I would not have lost him, but I could not catch him. I thought he got in the big tank. Sorry I am blabbering here. Anyways, back to my question, how long does it take them to mature? <A few months... sooner with more frequent feeding, water changes...> I do not mean an exact down to the minute answer or anything. On average, how long does it take before they are at least Ã'½ an inch or so? <A month or so> They are right now, about 1 week old and are about 3-5 centimeters, depending on which ones came first. They are eating well and defecating on a regular basis. Oh yeah, the other question I had is why does my second mother still look pregnant? <May be still> She had them about a week ago or so. Maybe not that long. Maybe only 3-5 days, but the first mother does not have the dark eyes spot that she did when she was pregnant. I am worried about her. I do not want to lose her. Out of the two mommies, she was the best. I do not think she eat any of them. I am sorry about going on like this. Feel free to edit what you need if you choose to post this. I cannot find anything on any of the websites stating how long they will be babies. I know not to expect them to be adults over night or anything, but I want to know how long I have to keep them isolated. Thank you so much. <We've got to produce some cohesive livebearer articles. Bob Fenner>

Swordtails Hi, I have a 10 gallon tank with a female and male Swordtail. I would like to know how I could tell if they are pregnant? I am only 15 and don't know much about fish. I have 8 other fish in my tank Pleco, 1 Chinese algae eater, 2 female fancy guppies, 2 male fancy guppies, and 2 zebras. And I would like to know how long I should wait until I but them in a breeder? <When pregnant the female will become very swollen and the black spot near her anal fin will darken. It can be difficult to time the birth, but usually she will try to hide and start to breath rapidly. The trick is to move her shortly before these advanced signs. Watch the dark spot. You may be able to see the fry's eyes shortly before they drop. Don>

Breeding Swordtails Hi. I have 2 swordtails, 1 male,1 female, and I would like to know what signs I am looking for to see if she is pregnant. Also how long I should wait to put her in a breeder? <The females belly will become very large and you should notice a dark area under the tail, look closely at this area. When you see little eyes in this area the babies are close to being born and she should be put in the net. She should still be fed so she doesn't eat the fry.-Chuck>

Swordtail repro., spaces between sentences 7/29/05 Hi, this is Lynn and I wanted to know if you can answer this question for me. Last night I noticed my pregnant female swordtail showing signs that she was going to have her babies, so I put her in the breeding trap. But it's been a few days now and she didn't have them yet.... Maybe I put her in too early? <Maybe> How can I help her have her babies in the breeding trap? <Just letting time go by. If the fish doesn't produce young in a few days, I'd return her to the main tank. Bob Fenner>

Swordtail breeding, studying 7/7/05 Hi, I noticed some articles about the swordtails, but didn't really see any answer to how you can tell is a swordtail is pregnant or not... <... seeing the eyes of the young near the vent... its enlargement, change to clear...> i have two swords, the one is trying to back in with his sword, and so would it be wise to put them both in a breeding tank? <Uh, no... the male stays out> or just assume she is already getting pregnant and just put her in her separate tank?? and if i should put both in, how do i know when to take the male back out? thanks a ton! Luke P <Keep studying... books, the Net... Bob Fenner>

Swordtail Breeding Our green swordtail just got done have about 35 babies. I have them in a 2 way breeder. Yesterday she got picked on and has a booboo on her side. How long should I leave her in the 2 way breeder. The "bully" fish is no longer with us but I didn't know if the male swordtail would pick on her. He is the only other fish we have. Please let me know when you think she should be strong enough to protect herself. Thanks! <I would watch her energy level. If she seems to be swimming well, then release her. I'm sure the male will chase and breed with her. But that's the life of a Swordtail. Add some plants or other places to hide if it gets too bad. If she's hurt so badly that she is having a hard time swimming, leave her in there for a few day. Make sure she's eating before you let her out. Don>

Swordtail Fry Questions Hi! I have a 10 gallon tank where a swordtail had babies several weeks ago. I don't remember exactly when, but the babies are mostly 3/4 inch. I want to separate out the sexes, but I have a couple concerns. First, when can I start to tell who is male and female? Right now, no swords are in evidence and no gonopodiums. Second, I know that a mixed sex tank needs more females than males, so will a tank of all males be fighting all the time? Also, the tank is looking pretty crowded right now. I have three adult females, one female-turned-male, ten babies, and a small panda cat. I just tested the water and found no ammonia or nitrites, and nitrates were around 30. I was really surprised. Shouldn't that be an overload situation? Thanks! Lauren <You will not be able to sex your fry until the gonopodium forms on the males. This will happen shortly before the sword forms. You want a high female to male ratio to spread out the male's sexual aggression. Most males get along fine with one another. Of course they are always exceptions to the rule. Each fish is an individual. And your stocking seems fine for now. You will need to move out some fry soon though. The best gauge of your stocking level is that nitrate test. If you can go a week without a water change and still have only 30ppm of nitrate, I'd say you're fine. 20ppm would be better though. While growing out the fry it's best to overfeed, then do more frequent water changes to keep things in line. Like the young of many species, the kids eat a ton and make a mess. Don>

Several questions re: Swordtail fry I have spent the last couple of months re-establishing our 55 gallon tank that was devastated by a temperature shock accident. The surviving fish from the tank are an adult female marble angelfish and two swordtails, one male and one pregnant female. We've gradually introduced new fish including a second also pregnant female sword, four juvenile angelfish, 2 Cory cats, 2 juvenile Plecos, and about 2 dozen tetras of different varieties. We also added some live and some fake plants and a good sized piece of wood from the LFS. Everyone looked great until two days ago, when I noticed that two of the swords had a little bit of fin rot and one was flashing against things. No sign of disease on any other fish though. Yesterday we corrected for a very small ammonia and nitrate spike and we added salt to help with the fin rot. <I wonder if the wood is at root cause here? Mal-affecting water quality... a sudden drop in pH, alkalinity would affect the Swordtails first here of all the life you list> We also began a course of treatment with MelaFix. <I would not use this "remedy"> Last night I noticed the original pregnant female showing signs of imminent delivery, so I put her in the breeding trap and sure enough we have babies, about 30 that survived the night of breeding trap malfunctions and forays into the main tank. They are now in a floating isolation/breeding tank. So here's the questions.. 1. Will the water treatments, salt, or MelaFix be bad for the fry? <Possibly> I was hesitant to continue to use the treatment but I did today anyway because I don't want all three of my swords suffering with fin rot if they don't have to. I just made sure to put the floating tank on one end of the tank and treat all the way at the other, so it would be nice and diluted once it reached the fry. Should I keep using it or no? <Do me a favor, and test the "drift-wood"... in a separate container... soak it for a day or three... test the water in with it> 2. My adult angel fish (Big Mama) won't leave the floating tank alone. She eats like normal at feeding times but she really wants those little tasty fries. Anything to be done about her? <Not much. Feed the fish more often, away from the trap> 3. My only other tank is another 55 gallon that is currently empty. We just did a %100 water change and replaced the gravel, so it's a completely fresh tank now. This is where we intend to move the fry, but I know you shouldn't put fry into a fresh tank like that. What is the best way to handle this and when should we move them? <Move water change water, possibly some of the "old/er" substrate into the new 55... wait a couple weeks...> 4. 55g is a whole lot of space for 30 fry, but it's all I have. What's the best way to feed them in a larger tank and should we try and keep a few other fish in the tank? <Frequent (a few times per day) finely ground (twixt your fingers) dried (flake, pellet) food... in the same area, routine> Uhhh.. that about covers it I think. Thanks. <Thank you for writing. Bob Fenner>

Several questions re: Swordtail fry > We also > began a course of treatment with MelaFix. > <I would not use this "remedy"> Well why not and what would you recommend? <<No real consistent beneficial action. May indeed be toxic to the fry. Would maybe use a bit of salt>> > <Do me a favor, and test the "drift-wood"... in a > separate container... soak it for a day or three... > test the water in with it> I took it out completely and replaced it with large rocks instead. <<Are you testing for it, their chemical activity?>> > 2. My adult angel fish (Big Mama) won't leave the > floating tank alone. She eats like normal at feeding > times but she really wants those little tasty fry. > Anything to be done about her? > <Not much. Feed the fish more often, away from the > trap> She seems to have gotten over this on her own. <<Ah, good>> > 4. 55g is a whole lotta space for 30 fry, but it's > all > I have. What's the best way to feed them in a larger > tank and should we try and keep a few other fish in > the tank? > <Frequent (a few times per day) finely ground (twixt > your fingers) dried (flake, pellet) food... in the > same area, routine> > Uhhh.. that about covers it I think. > Thanks. > <Thank you for writing. Bob Fenner> I picked up some Wardley's Smallfry liquid baby fish food and they really really seem to like it. Still feeding some well crushed regular and Spirulina flakes, but they seem to really prefer the liquid stuff. And since they are still in the floating baby tank, most of the uneaten portion slips through the holes into the main tank and the rest I very carefully suck out with a clean turkey baster. <Good technique> I am thinking that since they are doing so well in the floating tank, I will just leave them in there until they are too big, and then move them into the spare 55g. Would it be faster to get that tank going with good water quality if I put some small fish in there, in addition to putting water change water in there from the established tank? If so, what kind of fish would be best suited to be in a tank with juvenile swords? Thanks again. <Better to cycle "fish-less", though this tank is large. Bob Fenner>

Swordtail Due Date I have read thru all of the questions you all have answered but I still need a little help. I bought a green female swordtail yesterday, looking at her last night we realized she is pregnant. I can not see any eyes in the black area and I am trying to figure out how long to wait before I put her in the 2 way breeder. I do not want to put her in there too soon but I certainly don't want to miss her having the babies. Please help me. Thank you for your time. Heather <It's very hard to guess when a sword will drop. And it's always a guess. Watch the black spot. It will darken and seem closer to the skin as she nears her time. You may also notice her trying to hide from the other fish. Don>

Swordtail Due Date There isn't an answer to my question. <Sorry, possibly a glitch in the system. My answer is copied below. Don> <<It's very hard to guess when a sword will drop. And it's always a guess. Watch the black spot. It will darken and seem closer to the skin as she nears her time. You may also notice her trying to hide from the other fish. Don>>

Is my swordtail pregnant? Three weeks ago I was given a tank by someone who could no longer care for their fish. Included in the tank, along with some other fish, was a female orange swordtail. I believe she may be pregnant even though her male companion, a black molly, has since died. She has what appears to be a gravid spot and is swollen; however, she has been this way since I got her. Is she pregnant? <Maybe, maybe not> And if so, why hasnt she given birth yet? <May just look pregnant, may have given birth, eaten the young...> Also, her behavior has changed. She used to hide in one of the coral structures but is now floating/swimming around near the top (not dead) (mostly between the heater and filter). I would appreciate some help/advice. <Please read on WWM re. Bob Fenner>

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