Please visit our Sponsors

FAQs on Freshwater (and Terrestrial) Crustaceans 1

Related  Articles: Forget Crawfish Pie, Let's Make a Crawfish Tank! By Gage Harford, Freshwater to Brackish Crabs by Bob Fenner, Terrestrial Hermit CrabsInvertebrates for Freshwater Aquariums by Neale Monks,

Related FAQs:  FW Crustaceans 2 FW Crustaceans 3, FW Crustaceans 4, & & FAQs on: FW Crustacean Identification, FW Crustacean Behavior, FW Crustacean Compatibility, FW Crustacean Selection, FW Crustacean Systems, FW Crustacean Feeding, FW Crustacean Disease, FW Crustacean Reproduction & Crustacean Identification, Crustacean Selection, Crustacean Behavior, Crustacean Compatibility, Crustacean Systems, Crustacean Feeding, Crustacean Disease, Crustacean Reproduction, & FAQs on: FW Shrimp, FW Crabs, Terrestrial Hermit Crabs & Marine: Hermit ID, Hermit Behavior, Hermit Compatibility, Hermit Selection, Hermit Systems, Hermit Feeding, Hermit Reproduction, Hermit Disease/Health, & Crayfish FAQs, Crayfish 2, Crayfish ID, Crayfish Behavior, Crayfish Compatibility, Crayfish Selection, Crayfish Systems, Crayfish Feeding, Crayfish Disease, Crayfish Reproduction,

Crayfish and goldfish in ponds Hi, Do you happen to know if a crayfish would be good in an outdoor pond? Or would it eat my goldfish? Zac Lohrenz <Gage is apparently incognito... depending on the type of crayfish, size of goldfish... it might indeed be eaten... though I have seen these two species kept together. Bob Fenner>

Mystery Shrimp - Fun with Freshwater Inverts Hey all, <Hey, Chris> I have a rather odd hitchhiker that came with my bumblebee shrimp today. It's about the size of a large ghost shrimp, it's pincer arms are about as long as it's body <This alone screams "Macrobrachium!"  Now, Macrobrachium *what* is the question.> and are sort of banded in alternating pale red and grayish-black. LFS said it'd snuck in with the bumblebee shipment and hadn't injured/killed any of the bumblebees in the couple weeks it had been in their tank at the store, but they're not sure what it is. <Fun!> Well, due to various chaos today involving having to return/exchange the tank I got for Xmas (Marineland 10gs apparently have different dimensions than All-Glass 10gs), having to take relatives to the zoo for their annual Zoo Lights event, discovering I either need to buy an adaptor for the power cord and/or change the outlet the tank was going to be plugged into, my new 10g didn't get set up like I'd planned it to be. <Boy, when things go wrong!> So, for the night, the bumblebees (and unknown) all got placed in a 1 gallon tank with an airstone and some algae wafer bits. A short time later, both my sister and myself observed this unknown shrimp would wander the perimeter of the tank trying to pinch the tails of all the bumblebees (who'd jump out of the way). <Oh yes.  Macrobrachium shrimps almost all are aggressive meat eaters.  Fish, shrimp, anything that holds still long enough to be nabbed, are all at risk.> So the unknown got moved to a separate 1g, where he's mostly watching the bumblebees in the tank next door. <Dreaming of snacking, I'm sure.> (The bumblebees now appear much happier, munching away on the algae wafer and exploring instead of sitting in groups along the walls) <Probably feeling a touch safer, now that they're not potential meals!> So, can anyone ID this critter? <Your photos are quite unclear (no offense, just an observation) and therefore very difficult to tell anything for sure....  is it possible to get him into a position against a solid background?  It'd be especially nice to be able to see his first pair of legs, their shape, color, etc.  From what you've given me, the best rough guess I can give you is Macrobrachium japonicum.> I'm probably going to try and take him back, unless someone can convince me he'd be better behaved in the 10g with the bumblebees (and future fish inhabitants) rather than how he acted when stuffed into a 1g with them. <I would not expect him to change his ill manners, not at all.  But it certainly might be fun to hang on to him in his own tank, see what he grows up to be!  I'm sure he'll worm his way into your heart, even with an unbeatable appetite and a bit of a bad disposition.> I'm hazarding a guess it's some kind of Macrobrachium, perhaps? <Almost definitely.> The object it's sitting on in the photos is an airstone if that helps with scale at all. Given the day it's been, you're probably going to tell me I just got a future 5" monster shrimp that eats fish or something ;) <Well....  ;)  I do believe you're reading my mind!  I'm not at all certain on his ultimate size, though.  I'd guess somewhere in the neighborhood of a couple of inches.  Small fish would likely be at risk, and small shrimp, as you've observed, certainly aren't safe.  But again - don't give up on him just yet!  He may prove to be an endearing little dude, well deserving of his own tank.  Give him a chance, if you can.> Thanks again for any help you're able to provide,  Chris <You betcha.> --Addendum-- A friend located this photo that sort of looks like the unknown shrimp:  http://www.shrimpcrabsandcrayfish.co.uk/Shrimp.htm?Longarm.htm~mainFrame  (scroll down to Striped-Hand Prawn and click on the image). Although this site's photo is a bit redder than the one I have appears. <This picture looks very much like Macrobrachium japonicum to me.> And it seems to be the only site on the internet that uses the name Striped-Hand Prawn (aren't common names fun to deal with?) <Ugh.  I think the world would be a far less confusing place if we simply scrapped ALL common names.  *sigh*> Also, I already checked through the photos at   http://www.wirbellose.de/arten.html#GroÃarmgarnelen   to try and ID it with no luck (Remembered the site from when it was pointed out to me in the forums by vintage_fish <Hey, that's me!  ;) > several weeks ago in regards to a different species) <Try this one:   http://www.wirbellose.de/arten.cgi?action=show&artNo=220 .  Do please look very closely at the faint striping on the legs (I bet this is a juvenile or young female) and compare with your shrimp.  Also, try a Google search on Macrobrachium japonicum and check out some of the pics that come up.  If at all possible, try to get a clearer pic on a plain (perhaps black) background.  In any case, a fun little fellah to find out more about, if you can spare a tank for him!  Wishing you well,  -Sabrina>
Mystery Shrimp - Fun with Freshwater Inverts - II Hi Sabrina, thought you might get that e-mail ;) <It strikes me that there simply aren't that many shrimp-obsessed people around....  *sigh*> Thanks for the help, I think you may be right with the species, maybe this one just hasn't gotten its full color yet since it lacks the markings along its sides. I located this site: http://www.aquajapan.com/encyc/shrimp/palaemonidae/macrobrachium/japonicum_e.html <I've seen that one, hoped you'd Google the name and find it - glad you did> That has two pictures of females, the lower one reminds me a little more of what mine is. I'll try to get a better photo sent in (or posted in the forums) soon, still trying to figure out proper fish photography with a digital camera (best results so far have been with tank light off and flash on in that 1g). <"I feel your pain" - my shrimp photos are currently far worse than yours, so don't feel bad, not at all!> The bumblebees are now in the 10g (blending in with the Fluorite), <They are goo at that.> I was going to try reintroducing the bully in the 10g after a few days (and after I add some rockwork for hiding spots) but given this info, I'll just keep him in the 1g while I figure out what to do with him. <A good plan.  Surely you've got room for a smallish tank somewhere?  He'd probably be fine in the 1g for a while.> LFS has informed me their return  policy on livestock only applies to dead livestock. < .... That's simply insane.  And stupid.  And insane.  So, let me see if I've got this right....  They won't take it back and sell it, but if you kill it and bring it in, they'll refund you?  That's....  Insane.> Happily, one of the other Aquamaniacs moderators has offered it a home if I don't/can't keep it, since she has two "shrimpzillas" already that she was sold as ghost shrimp (she thinks she's narrowed down the ID of hers to either Indian or Thailand prawns). <Heh, if it weren't that shipping costs suck, I'd gladly offer the li'l guy a home.  Do consider keeping him, I think you'd have fun learning about him.  The larger, aggressive shrimps can have a lot of personality (or seem to, if you're a shrimp nut like me!).> Thanks again for the help,  Chris <Any time.  Wishing you and your shrimpums well,  -Sabrina>

Little Eaters of Algae Hi! <Hello!> I have an Eclipse 6 aquarium.  I have had it for 6 weeks....it is finally done cycling....no ammonia an no more nitrites.   <Wonderful.> I have 4 platies and 1 Cory catfish.  Is it okay to purchase an algae eater....can you recommend something small?   <I can, indeed.  But you'll find I'm extremely biased, here - getting into my favorite subject, an' all....  Your best bet all the way around is to look for freshwater algae eating shrimps.  These pleasant little creatures come in pint-sized packages packing a punch to pulverize your putrid algae problem - uh, sorry 'bout that....  Do try to find cherry shrimp or bumblebee shrimp, as these seem to stay the smallest and are avid attackers of algae.  You could easily keep half a dozen of either of these kind in your tank.  If you can't find those, next in line are 'the' algae shrimp, or Amano shrimp, the well-known Caridina japonica.  These get significantly larger, so you'd probably only want two or three in your tank.  If you're lucky, you might find 'rainbow' shrimp in as contaminants with the Amanos.  These have a slightly more prominent 'hump' in their back, though not much, and they have a few stripes running perpendicular to the stripe down their back (the Amanos lack these stripes, and the stripe running down their back is much narrower).  They also become neat colors as they age, blue-green or red-brown, and they stay smaller than the Amanos, too, though not as small as cherry shrimp or bumblebee shrimp.  And, failing shrimps altogether, you'd probably be safe to get a single Otocinclus catfish.  These tiny little guys do a number on algae, but aren't nearly as fun as shrimp (uh, in my obsessed mind, that is).> I don't have much algae yet.   <Good!!  Though you might have to feed your new algae-eating-critter on other veggie matter, too.> I don't want to purchase a larger algae eater because of the size of the tank.  And the algae eater has to get along with catfish and platies.  Is the catfish good enough???   <Corys don't eat algae much to speak of (they also like to be in groups of three or more, but in a small 6g tank, that's virtually impossible).  Whether you choose an Otocinclus or any of the abovementioned shrimps, you'll be absolutely fine, in terms of compatibility.> Also, with a tank this  size.....should I do a water change about every 3 weeks....like a 25% water change?   <Well, I'd do water changes closer to every week, but only on the order of 10-15%.  Less water, more often is usually the best bet. Thanks! <Any time!  -Sabrina, the shrimp-obsessed>

Classroom Tank >Hi crew! >>Good morning, Joy, Marina here. >One of my students took home the class pet for summer vacation, renamed her, and now my red eared slider has a new home and I have a 55 gallon tank to fill.  Help!!  I've purchased an aquarium divider.  I want to know can I have a crayfish or lobster on one side of the divider and a shrimp and some type of aquatic or semi-aquatic frog on the other.   >>Yes, you can do this. >Possibly a fish or two if you can recommend ones that won't be eaten. >>Not with the crawdad/freshwater lobster, but if you have something like a small leopard frog on the other side, then you can put in mosquito fish or similar small fish.  Also, consider land hermit crabs (the Caribbean variety).  I don't think they can pinch any worse than a crawfish!  They do require a different setup, though.  If interested, check out http://www.hermit-crabs.com for best information. >My concerns are having species that have the same temperature and water hardness requirement. >>Not exactly a worry with frogs and crawdads, very hardy, as are most commonly available tropical fish. >Some of my students have vision issues, so could you please recommend colorful species (our school uniform colors are white and blue, I would love to say my aquarium creatures are dressed in uniform). >>Sorry, but most colorful species are VERY specialized and difficult to care for, and the ones that I can think of that would match your school colors are poison dart frogs.  Even though their stay in captivity and lack of variety in diet seems to seriously reduce toxin levels, still not a good idea in my opinion (mostly for meeting their requirements).  There does exist, however, a BLUE freshwater crawfish that is also known as a freshwater lobster.  This may take some searching to find.  Marina

Diatoms, and the shrimp that eat them Hello! <Hi, Lemia!  Sabrina here, today, fighting the algae war with all you algae-hatin' folks> I've been reading the many FAQ's and other info on your site concerning Diatoms.  Most of them seem to address this issue with regard to marine/saltwater aquaria (unless I am misunderstanding some of the abbreviations).   <Nope, no misunderstanding, you're right.> I have a freshwater aquarium that is almost 4 months old.  Some of the specs are as follows:  46 gallon, Emperor 400 Bio-Wheel filter.  No live plants or rocks.  Water levels as follows:  Ph-7.0, Ammonia <.5 ppm, Nitrite=0, Nitrate=60 ppm (I will be doing a water change tomorrow). KH=5 dKH and GH=9 dGH.   <Fish, yet?  Get that ammonia to zero.  And YIKES! at that nitrate reading!!  There's the cause of your problem (or at least part of it)!> My problem is that over the past 2 months I 've been developing diatoms that just keep getting worse not better.  Before I confirmed they were diatoms I tried increasing the lighting, <Increasing lighting will only help the algae grow....> an algae eater (neither helped at all or made things worse) <Depending on what fish you mean by this, it might not even recognize diatoms as food.> and a chemical algaecide (only helped a little).   <Yuck.  This should be kept as an absolute last resort.  Could be quite harmful to plants, should you ever choose to keep them.> I have since confirmed through my local fish store that I definitely have diatoms. <Kind of a brown, mucky, dust-looking stuff?> They believe (as do I) that it is due to excess silicates in the tank.   <Although silicates are likely a contributor to the problem, the extremely high nitrates are very much to blame, too.  Also high phosphates are definitely suspect.> They recommended use of the Phosguard product by Seachem.  I began using the product a week ago with no noticeable improvement.   <Cool stuff, really.  I've not had need of it in my freshwater aquaria, but it is helpful in my nano-reef when necessary.> I purchased a silicate test kit and determined that the tank has 1.5 ppm of silicate.  My understanding is that for freshwater aquaria that level should be at .02 ppm.  I have tested my tap water, which is what I use for water changes and evaporation top offs and determined that it has over 2 ppm of silicates.   <Yeah, probably a contributing factor, but you've got a lot going against you what with the super-duper high nitrates.  I'd like to know your phosphate levels, too, I bet they're high.> As a result, I believe that continued use of the Phosguard will not remedy my diatom problem.   <Correct.  You need to get to the source of it, cut off its nutrients.  Phosguard will help, though, in starting to control the problem.> I have been reading up on diatom filters but from what I read, I'm just not sure if they are the correct solution.  I also saw on your website notes on Reverse Osmosis water?? Where would I be able to get that?? I also saw info on Deionization units/water??   <Please start reading here:   http://www.wetwebmedia.com/rofaqs.htm  , then if you're still uncertain, read some of the gobs and gobs of related FAQs :)  I think you'll have more than you ever wanted to know.> I am hoping you can expand on what some of these items are, what they'll do, how will they effect other factors in my aquarium, etc.  Also, if you can give me your feedback on what the best solution would be to remove the diatoms and manage the tank to prevent future breakouts I would be most appreciative. <Ahh....  Now I start in....  First off, please do consider planting the aquarium.  Anacharis/elodea will help with sucking up some of the nutrients, as well as feed some fish.  You might want to plop some water lettuce in the top of the tank, to provide shade as well as to soak up nitrates.  Water sprite, Vallisneria, Amazon swords....  the list goes on and on.  But even more fun....  Bamboo shrimp.  Also called wood shrimp or Singapore shrimp, Atyopsis moluccensis are EXTREMELY adept at consuming diatomic algae.  When first starting out my 72g planted aquarium, I had major diatom issues while the tank was still extremely sparsely planted.  I grabbed some Amano shrimp (Caridina japonica) to try to help, but they weren't too adept at nailing the diatoms (though they did a number and a half on some green algae that was forming).  Just for kicks, I dropped in a wood shrimp.  The thing was a diatom lawnmower!  He truly left an obvious path behind him where he'd been grazing.  You could track him by the path in the stuff.  Just one single wood shrimp in a 72 gallon aquarium cleared up the diatoms in less than a week.  However, I will caution you - there is a drawback to this shrimp - once the diatoms are gone, you'll have to drop in food for him regularly, or he will starve.  These are filter feeding animals by nature, and will simply hold their 'fan-hands' open in the current in the wild to catch bits of food suspended in the water.  But our tanks are just too clean for that to happen; they really must have food that will break into particulate matter (I use Hikari sinking wafers/pellets) for them to 'shovel' into their mouths.  If ever your shrimp is 'fanning' in the current for long periods of time, this is likely indicative that he is starving to death.  From my experience, when well fed, they will only filter-feed when they are at rest.  One more drawback is that you can never, ever use copper in a tank containing invertebrates.  If interested in shrimp, you may also want to dose your tank with iodine weekly at a rate of one drop of Kent's iodine supplement (made for reef tanks) per ten gallons of water.  After I started doing this in my tanks, there was an extremely noticeable increase in health, activity, growth, and color in all of my shrimp species.  Wonderful animals, they are.> Thank you in advance for your assistance and for your patience in reading my lengthy note. <And thank you for my patience in my lengthy reply!  (I'm shrimp obsessed ;D ) Lemia M.

Hermit Crab Reproduction? Nope - Just Molting - 8/21/03 We apparently had a male ("Jupiter")  and a female ("Crustaceous") hermit crab.  They were reasonably active (when it was safe I let them out to walk around an open space on the floor).  They enjoyed their food and drank from their sponge.   They always slept cuddled closely together. <Hmmm... no mention of daily spraying of them/the tank for humidity... helps them to breath easier - literally. Too many hobbyists are not informed of this and the crabs suffer slowly over time (evidenced by inactivity, incomplete molts, etc)> Then Crustaceous seemed to be getting antisocial and was off to herself most of the time.  I realized she was in the same spot through the day and then also through the night.  When I picked her up, she just about fell out of her shell - and of course she was dead.  But her body looked really weird - as if there was almost nothing inside the skin.   <this was simply the molt my friend> I planned to bury her with the rest of our long last hermit crabs, <yikes... how many bodies? I'm wondering if they just haven't been petering out slowly from lack of spraying/humidity?> but I thought I would clean the shell and keep it. I was shocked when I looked into the shell and saw what looked like a very tiny fully formed hermit crab claw.  It was orange/red in color.  I determined there was no life in whatever it was and tried to pry it gently from the shell.  It was a tiny  formed crab. The legs broke off as it just fell out once it was loosened.  That also seemed as if there was not much (if anything) inside the shell. There was an odor so my husband quickly wrapped it up and disposed of it.  I am sorry to say we didn't just bury the whole thing in the yard.  But, I was afraid of disease and the whole thing was so weird I wasn't sure it really happened.  Jupiter is not looking too well right now either.  I totally scrubbed their home, changed everything and am trying to keep him safe if there were any germs.  But, I am afraid we are going to lose him. I have been obsessed with that baby crab - because that's what I'm sure it was - and regret I hadn't seen your web site before I disposed of it.  I would appreciate your comments.  Ann <please do buy a handbook online or at your local pet store on keeping hermit crabs properly... much data online too. That was no baby as you might guess by now, but the shrunk molted living crab. It sounds like you need a spray bottle in use by the tank ;) Best of luck. Anthony>

Hermit Crab Reproduction? Molting - 8/24/03 Thank you so much for your prompt response.  I feel terrible to know I caused its death.   <no worries, mate... their natural lifespan is not so long... and the crabs we collect are generally adults of an unknown age> I do spray the crabs (obviously not enough) and make sure they always have plenty of clean water in their dish and sponge.   <excellent to hear... and do check out the following links mentioned to us by a daily reader after seeing yours and other recent posts: http://www.landhermitcrabs.com http://www.hermit-crabs.com > I have kept them successfully for years at a time.  And I have read up some - again obviously not enough.  I only learned from your site about their need for salt, though I should certainly have figured that out considering they come from the shore.  I never, never heard anything about the crab molting - not from any of my friends who have many more hermit crabs than I have. <my goodness... tis a common, albeit secretive occurrence. The molts are generally eaten> And believe it or not, I did even buy a hermit crab book at the pet store when my granddaughter brought the first hermit crab here.   <excellent... you really are quite on par my friend. Keeping them for a couple of years is quite good too> But she took the book, and I had the crab.  Not a very good combination. Please be sure no other hermit crab will suffer in my hands.   Thank you again. <always welcome... best of luck! Anthony>

Land Hermit Crabs and Softened Water? - 8/14/03 HI, <howdy> can I give my land hermit crabs water from my tap if we have a water conditioning system that uses salt? Kara <not recommended, my friend. The salt exchangers impart excess chloride that has been demonstrated to be a problem with some animals. Please do bypass the softener and/or keep a jug of spring water handy (not distilled... too pure). Kindly, Anthony>

Hermit Crab Mites? I have had hermit crabs for 4 months.  I noticed really small, tan/clear bugs in the cage, crabs, and food dish.  I cleaned the cage, but they are still there.  Where are they coming from?  How do I get rid of them?  Do they hurt the crabs?  I have lost two crabs. <Hmm, sounds like mites to me, nasty little buggers.  Check out the site below for more info. http://www4.tpg.com.au/users/vanessap/hermit/cs/cs_mites.html#grainmite   Best Regards, Gage>

Land Hermit Disease Hi WetWebMedia crew, <Hello, Gage here.> About two months ago I have purchased two land hermit crabs. They seem healthy to me but recently there is some talk about a hermit disease that kills whole tank full crabs. They don't seem to shown any significant symptoms.  Do you know anything about this?  Are there any known diseases that hermit crabs can carry and that are dangerous to humans (like salmonella, cyst causing parasites, etc)? I have a 2.5 year old son who loves his crabs. I make him wash his hands every time he handles the crabs but that is pretty tough for a 2 year old and I am worried.    <I am not sure if they are as dangerous as say, a turtle, but I would definitely keep up on the hand washing, better safe than sorry.  http://www.hermit-crabs.com has a section for popular myths, they mention Hermit Crabs spreading disease.  I would start searching there.   Best Regards, Gage > Thanks in advance,  Iklil Palanduz

Land Hermit crabs 7/13/03 Hi there I was wondering if you can help us. We have 3 land hermit crabs. The larger one of them (Sherman) was just purchased a few days ago, he was active and happy. This morning I found him in the middle of the tank almost all the way out of his shell and limp, but, when I touched his legs, he very slowly moved back into the shell and has not moved since, (when you do touch the legs it will have very slow movements). <have you been misting these creatures daily or nearly so with fresh water? They need the moisture to respire properly> I have moved him into another tank. Once I moved him out and had a closer look at him, I noted a lot of dried up and peeling skin? Its eyes are droopy with no colour. <the lack of water if a common error/mistake> I found him in the middle of the tank on top of some food, taken from the dish. The day before I didn't notice anything wrong, He did spend a lot of time in the water dish and food dish though. The temperature of the tank is between 78 and 82 and the humidity is around 70%-80%. <hmmm... my apologies. It sounds as though you are quite aware of the need for hydration. If a rinse or spritz of the creature does not help... we are looking at another issue indeed> The other 2 crabs are fine and active. Is this guy dying. Please help me I am the mother of 3 children who will be very upset when they wake today. Thank you Sherman's mom <hmmm... I suppose there are many possibilities... stress-induced trauma from recent import not the least of them. I regret that I know little more about this hardy creature than you/we could find with skilled keyword searches on the Net and in books. Anthony>

Hitch Hiking Hermit Crab Hello I have a problem that maybe you could help out with.  Over Easter break I vacationed to Aruba.  Along the shore Collected shells.  When I arrived home I realized that the only thing I brought home from Aruba wasn't just shells.  A hermit crab no bigger than 1 inch tagged along. <Whoops> It has small blue legs and a huge abdomen.  I gave it a shell to go it and it did. So now what?  I have this little hermit crab that I don't want to kill or let die and I have no clue how to care for it or what to feed it. Please help. Thank you for your time and please respond, Tom Schaner <There is a ton of information on keeping land hermits on the web. You should be able to find info on housing and feeding requirements, most pet stores will have hermit crab food.  I would start with a search using Google.com, and a browse through our FAQs on Crustaceans. -Gage http://www.wetwebmedia.com/FWSubWebIndex/fwcrustfaqs.htm  > My Little Lobster (terror!) Hello, I hope you can help me! I recently rescued what I believe to be a lobster from a friend who had moved it to a TINY tank after it removed the tails from all of his fish! It is about 3 inches long (when my friend bought it he was told it would grow to about a foot long) and resembles a crayfish at the moment but has a bluish tinge to it. My clever friend seems to know nothing about its care and I have spent the day searching bookshops and the web for info on how to care for it with no success. So I basically need as much info as possible or recommendation of a good book (which I can get in the UK). <Mmm, sounds like a Cherax species. Please see here: http://www.wetwebmedia.com/FWSubWebIndex/fwcrustaceans.htm and use the names given for the identified animal a spin (insert) on your search engines. Bob Fenner> Thanks very much Sarah

Fresh water shrimp can fresh water shrimp cause disease in humans? thank you <Not as far as I'm aware by simply handling... however, I would cook any thoroughly if consuming. Bob Fenner>

Sexing ghost shrimp I'm trying to breed ghost shrimp and I was wondering how to tell the difference between a male and female ghost shrimp. <Mmm, is this the ghost shrimp of the family Callianassidae? Or the Palaemonids that are sold as food animals in the pet-fish trade? For the latter please see here: http://fish.orbust.net/ghostshrimp.html Bob Fenner>

Reproducing blue lobsters Hi folks I'm new to this site so forgive me for any indiscretions. <No worries> A friend has asked me to find out.... his blue lobster has eggs on it should he leave it in the tank it shares with an Oscar and Piranha or should he put into another tank that it doesn't normally go in but it has other blue lobsters in? <The females will often give up on the eggs if she is disturbed at all so it is recommended that you leave her where she is.> Thanks for any help. Billy <You're welcome. Ronni>

Shrimp/Crayfish As a Valentine's Day gift for my two sons, my husband purchased two African Clawed Frogs, while the man at the pet store was trying to catch the albino frog, he came across a little guy my oldest son likes to call "Pincher."  He gave him to us for free since he wasn't sure what he was.  I think he's either a shrimp or crayfish of some kind.  How do you tell the difference between the two?  He's about 1 inch long with two pinchers and a grayish/brown color and a flat fan like tail.  I would greatly appreciate your answer.  Thank you. Susan <Hi Susan, generally crayfish are larger than shrimp.  It's hard to say without a picture.  Does it look like any of these: http://www.thekrib.com/Fish/Shrimp/ Regards, Gage>

Shrimp/Crayfish I am going to try and get a picture sent to you of "Pincher". <Awesome> I looked at the site you sent and couldn't find any one shrimp that looked enough like him, they all resembled him but not enough for me to say he's a shrimp.  The only other way I can describe him is he likes to hoard food, he at first didn't mind the African Clawed Frogs but then suddenly started to chase them around and even pinched off some of the little albino frogs toes. <Maybe a crayfish, they are pretty aggressive.> He has dug himself a little home in the gravel under a decoration in the tank.  I know this probably doesn't help you much more, so like I said I'm going to try to get a picture sent to you. Thanks for all your help. <In my experience freshwater shrimp will usually do their best to hide and avoid confrontation with anything and everything.  This sounds like a crayfish to me, I named mine "fish pinchin' crawdad" I'm working on a country song about him. A picture would be great. Regards, Gage> Susan

Friends for our Tiger Oscars? We have a 55 gallon freshwater tank that is currently home to four Tiger Oscars (approximately 2") and they're getting lonely.  Knowing that these fish can be pretty ferocious, we're not sure what we can safely add. <At this size you should be able to safely add any similar sized fairly aggressive fish. There are several other Cichlid species would work nicely. Just make sure to get some that like the same water parameters.> We've got our eye on a blue or red lobster that's available at our local fish store that are a little larger than the Oscars (maybe 3" in length?).  We're concerned that either the Oscar's will attack the lobster, or the lobster will attack the Oscars. <I don't have any experience with freshwater crustaceans so can't say for sure. I would be more worried about your fish picking on the lobsters than the opposite but on the other hand they may not. Despite their reputation, Oscars can be fairly docile fish. My LFS has a large (10') Oscar housed in a tank with a bunch of baby Frontosas and they haven't had any problems. They did also have some Rusty Crabs in that tank but the crabs were going after the babies so they removed them. Ronni> What other types of fish and/or crustaceans do make good tankmates for Oscars?   Thanks, Fred

Re: football shaped creatures I bought some live plants for my freshwater aquarium at the pet store some time ago. Some other stuff must have come along because pretty soon I had some snails. I also got hundreds of little "bugs". These things are barely visible. They scoot around in the tank. Under a microscope they look like little footballs. Their bodies open up like a clamshell and little hairs come out of the opening and propel them around in the water. <<Not sure exactly what they'd be but they are most likely harmless. I've heard of similar creatures in other tanks, most of the time they seem to go away on their own after a bit. You might use the Google search box at www.wetwebmedia.com to see if you can find anything similar. It is a good idea to fully quarantine any new plants just as you would new fish to prevent these types of things and also diseases from getting into your system.>> The only thing in my aquarium is a little African frog and some of the snails. The frog is fine, but the snails keep dying. I don't know if the little bug thingies are responsible for the high snail mortality rate, or if it's something else. Any ideas???? Russ <<I doubt these are causing the death of the snails. FW snails multiply very rapidly and I'm sure there is a lot more die-off than most people generally notice just because there are usually fish and other distractions in the tank. I wouldn't worry too much about it unless it is causing problems in your ammonia/nitrite levels. Ronni>>

Re: football shaped creatures After a little more research I discovered that these things must be some kind if ostracod. <Yes! Nice pic!> They look like this except their shape is more like a football. Supposedly they eat algae. I couldn't find anything that said they were harmful to snails. <No, they (ostracod crustaceans) aren't> So these little guys seem to be thriving but even though I change over 50% of the water every two weeks my snails keep dying?? <I would check the difference between your new and old water and store and match their characteristics before using. Please see here: http://www.wetwebmedia.com/water4maruse.htm Bob Fenner>

Crayfish Starting from scratch here.  We have success in sustaining crayfish.  We have had zero success in growing the tank population.  What could we be doing wrong? <Likely the ones there already are eating each other. Especially when they molt (shed their external skeleton, to grow) crayfish are very susceptible to predation. Maybe adding more rockwork, some plants (plastic or real) will help boost your population. If you're expecting them to reproduce, there are a number of reasons why their young may not be being produced or likely being consumed as well. Bob Fenner>

Land hermit crabs hi, I brought 10 little land hermit crabs back from Mexico for my son for Christmas. they are in a large Plexiglas tank with little stones and some awesome climbing sticks. I have hermit food and a sponge that I keep quite wet. I mist them daily and I have provided lots of shells. (they are changing them like crazy) two of them are connected right now and they are making "clicking noises" are they fighting? how do they mate? can you give me any advice?  when I took them, I vowed to keep them alive and I want all the info I can get.    thanks,   Julie Swann <Hi Julie, I am not familiar with the actual mating ritual of the land hermit crab.  I would be willing to bet they are fighting, most likely over a shell.  While searching on Google.com I stumbled upon the link below, it appears to have a lot of information on land hermits http://www4.tpg.com.au/users/vanessap/hermit/cs/cs_gender.html Hope this helps, Gage>

Ghost Shrimp Hi! Can you tell me what ghost shrimp eat? <Just about anything you offer them meat based.> Thanks, David Muir <You are welcome. -Steven Pro>

Re: (land) hermit crab I'm not sure if land crabs are your area, but if so I would very much appreciate a reply.  I have had a land hermit crab for over a year now.  He's to all appearances happy and healthy, except he has lost quite a bit of color.  In fact, the last time he molted he was just about translucent.  He has a choice of many foods:  Hikari "Crab cuisine", Tetra/Terrafauna "hermit crab cakes", Aquadyne mix of goldfish food and vegetables, and Hermit Haven hermit crab food.  He has a large water dish with sponges, shells, and Cholla wood.  He also gets salad or other veggies from my meals.  His water is distilled, and I change the shells when it appears that the calcium has come off of them. Do you have any ideas as to what could be happening to my crab?  Thank you very much for your time. ~Melissa <Hi Melissa, it sounds like you take excellent care of your hermit crab.  Varied diet, good water, clean living, the only thing that I can think of that may be missing is sunlight.  A full spectrum daylight fluorescent bulb may help him/her out.  My experience with land hermits is limited, but it sounds like you are doing everything correctly, I would try adding some daylight.>

Freshwater shrimp? Dear Crew, We have unfortunately had a small tragedy in our freshwater tank (240L, ph6.5-7, temp 75-77, nitrates 0, hardness 3-4)...in with our neon tetras (11), black widow tetras (6), Otos (5), Rams (3), Corys (6) we had had 5 "red claw shrimp". Now from the pictures on your site and on all of the other freshwater shrimp sites, they look like ghost shrimp, but are a reddish/orange color. We bought them from one of the LFS staff who lives in our area and breeds them in her tank. The biggest of these fellows is about 2 inches long, and the smallest about 1 inch. Until yesterday all was well (how can you tell there's going to be a but) but yesterday evening I noticed small red shrimp on its back, scrabbling a bit. I thought this was strange, so turned him over and moved him into a sheltered corner, he seemed to be struggling, so I wondered whether he was molting and turned off the tank lights to minimize stress and left him to it. This morning at work I have received an e-mail from home telling me that small red shrimp is no more. So now I have 2 questions, first of all, do you have any ideas what species these fellows might be? and secondly, what could have killed small red? his legs and claws looked strangely pale and he seemed sort of bunched up (cramp?) but apart from that we have no clue... Any suggestions would be useful, we want to prevent the same happening to the other 4. Thanks for your time. Nicola <Hey Nicola, sorry to hear about your shrimp. It is hard to get a positive ID without a good picture. The common ghost shrimp will not reach 2in. Take a look at the link below, is it one of these guys? http://www.calacademy.org/research/izg/SFBay2K/ghostshrimp.htm My first concern would be water quality. I would do a good water change, and add a poly filter to absorb metals and many other contaminants. Keep an eye on the other shrimp, if it starts happening to the others we will know that it was not a molting complication and can start troubleshooting from there. Let us know how it goes, Best of Luck, Gage.> Nicola Blay, BSc, MSc International Zoo Veterinary Group

Blue Marron Mr. Fenner: I have found a site with what I had hoped would be an article on how to care for my new Blue Marron on WetWeb. However, there was no article where it should have been. I am in need of some assistance as to caring for my new friend and would appreciate any information that you could provide. <The only related material we have presently is the coverage of freshwater crustaceans in general: http://www.wetwebmedia.com/FWSubWebIndex/fwcrustaceans.htm and the FAQs beyond. Perhaps you will pen an article on this species. Bob Fenner> Thank you.

Crayfish Hi Bob Fenner I have a 2.5gallon tank with a crayfish and a 29gallon hard alkaline cichlid tank with a divider. I want to move the crayfish to the empty portion of the 29gallon tank and was wondering how to go about acclimating him from his neutral water. <I would "drip acclimate" the crayfish/crawdad to the new water by placing it in a lower position, dropping half the water out, and use a length of airline tubing (with an adjustable knot) to drip (about one drop a second) the cichlid water into its smaller system... Most species (yours... likely an astacid... maybe Procambarus clarkii?) will make this transition easily... after this abrupt mixing, just place the animal by scooping it into a bag or plastic container underwater and put in the larger system> Ps. I appreciate your past help, and the speed at which you have replied. <You proverbially "ain't seen nothing yet". Bob Fenner>

Crayfish I was wondering wither I could successfully keep a crayfish in a 2.5gallon tank with a sponge filter. <it would be a little cramped, but it would likely work too. They are incredibly hardy creatures.>

Macrobrachium rosenbergii information Robert, Around 14 years ago I purchased three "Blue Lobsters" from a pet store in Mt. Pleasant, MI. Later on I learned that they were known as Macrobrachium rosenbergii. These three invertebrates were the most interesting aquarium pets that I had ever owned. They are long gone now, but I recently purchased a 125 gallon aquarium which I intend to put my larger Cichlids in. Thinking about what to put into the empty 55 gallon, I remembered the "Blue Lobsters" which I loved having in the past. My question is where can I purchase them??? I can not find them anywhere in the West Michigan area. Whenever I ask pet shop employees they look at me like I am crazy!! If you might have any information that might be helpful please e-mail me back. <These crustaceans are still about, though not near as popular as they were years back. This one species is widely and intensively cultured as a food organism (mainly in the Far East). It and a handful of new species of interesting prawns, shrimp and true lobsters can be had from larger retailers and etailers. Please contact the folks on our Links Page here: http://www.wetwebmedia.com/links.htm to start your search, and ask your local fish stores if they'll please look, special order one, more for you. Bob Fenner> Thank you, Andy Shearer

Blue Marron, Brown Algae and dying Guppies Hi Robert, <<Greetings Mark, JasonC here.>> Firstly I will go through what I have and my experience, that may help to answer my questions. I have about 8 months experience with a 3' 126 litre home made tank in which I have 5 Barramundi, 1 Eel Tail Catfish and 1 Bumble Bee Catfish. This tank has an undergravel filter and an Aquaclear 200 filter and is decorated with mangrove root, rocks and various plants. I have found this tank a pleasure to observe and maintain. Luckily there has been no casualties and all 7 fish have grown considerably, so much so I am thinking of building a 4 1/2 foot tank with some glass I have, to accommodate there size. <<good idea.>> Because of the Barra's ferocious appetite and the cost of their food I have built another 3" 126 litre tank which I have 3 Hockey Stick Tetra's, 5 Cardinal Tetra's, 2 Male Guppies and 3 Female Guppies and about 25 Baby Guppies. The Tetra's are in the tank for a bit of colour while the Guppies are being bred as feeder fish to supplement the Barra feeding. This tank also has an undergravel filter and an Aquaclear 200 filter and is decorated with rocks and a variety of plants, some to make it easier for the baby Guppies to hide. This tank is only 2 months old and has been a little challenging as I have had a few problems with Guppies Dying and a brown algae that seems to be growing on everything, including the upward facing leaves of the bigger foliage plants. I am constantly cleaning this algae from the rocks, upward facing leaves and the glass sides. Then vacuuming as much as I can before it settles. I feed these fish flakes and for the babies Liquid Small Fry. Firstly can you help with the brown algae and how do I control/eradicate it? <<You should avail yourself to the materials on WWM, of interest to you would be these two algae-control articles, one on fresh water and one on planted tanks: http://www.wetwebmedia.com/fwalgaecontrol.htm http://www.wetwebmedia.com/algcontagb.htm >> Secondly, I don't understand why the Guppies are dying. They seem to swell in the stomach and after death bust open through the anus. <<According to Bob, this is unfortunately this is indicative of a bacterial condition [Chondrococcus or Columnaris disease] which can only be cured with the use of Neomycin sulfate. You could also use the Tetra medicated flakes, but you should probably evaluate the cost/benefit of this exercise. I would certainly stop adding new fish to this tank until you have this under control.>> Thirdly, I have inherited a Blue Marron and am keeping it in the breeder tank and was wondering if this is ok with consideration to: How do I feed it with the correct diet? If kept feed properly will it still be a threat to the other fish? Is the neutral PH of the community tank ok? <<read up on these guys: http://www.wetwebmedia.com/shrimpfw.htm >> If there is to much in this email the main thing I am concerned about is the Blue Marron issue, followed by the brown algae then the dying Guppies. Any help would be greatly appreciated as at the moment I am running totally blind. <<Definitely go through the WWM site, there is much information there to help you.>> Thank you Mark <<You are quite welcome. Cheers, J -- >>

Please help !!!! hey, I have a tropical aquarium with a small blue Marron <This is a Crayfish for browsers: Cherax tenuimanus> about 3 inches long and went I went to check my tank this morning I found the blue marrons shell without him in and than I looked under a rock and he is there and he isn't moving is hibernating or some thing and growing back a new shell or is he dead please write back as soon as possible thank you for your help. <In all likelihood your Marron is indeed hiding while its new exoskeleton is hardening. Do leave the old one in the tank (sometimes they are eaten to help build the new one) and the crustaceans hiding space intact... It should come out in a week or so. Bob Fenner> From Ian

Any non-fish for a community tank? Mr. Fenner: Thank you for your prompt reply and helpful information in response to my questions about freshwater lobsters and crayfish. <You're welcome> (My interest in these crustaceans and the like is purely non-gastrological, though) <oh> If lobsters and crayfish are not ideal candidates for a community tank... are there any invertebrates that are? Any that won't be eaten by the fish? <Yes... depending on which species we're talking about... of a certainty there are ones that can/do/will eat each other> Must have fish and invertebrates (and not eat them) too! Please help! AHR <Do take a read through the various fresh and brackish water sections (livestock sub-sections) posted on WetWebMedia.com for input on selection, choices. Bob Fenner>

Update Dear Bob, I thought I'd let you know that Oscars et al are doing well. We have been testing the water daily - everything coming up normal, and doing a 20% water change every other day. I would once again like to thank you for your help (my fish thank you too). <Great to hear of the improvement> We set up a 40 gallon tank yesterday and will follow your advice and let it cycle for a few weeks before adding livestock. That will give us time to plan what goes in and keep the stress level to a minimum. I am thinking of putting a couple of crayfish (Astacus) in (cause I like to watch them) <Very interesting animals... I had Procambarus clarkii (the most common "crawdad"... used as "ditch bugs" in Louisiana, Texas, and California when I could get enough of them...) for years> and need to figure out what to add with them. I haven't had an aquarium since I was very young (too young to know how to look after them) and I had forgotten how enjoyable and relaxing it is to watch them. <Look for livestock that's fast, aware, large enough... but not too susceptible to crayfish dinners!> Thanks again for your help and do/will keep in touch. Linda <Do so. Be chatting. Bob Fenner>

"Craw Dads" Dear Bob, After our emails earlier today I searched the net for info re crayfish. Correct me if I am wrong, but not too many people have an interest in these creatures.  <Not that many... surprising for how many species, interesting biology...> I have spent more than a couple of hours searching and other than recipes on how to prepare them, I have come up with three articles. I live in Canada and to see these creatures is a relative rarity. I suppose elsewhere, i.e. the U.S. and Australia, they are considered too common to get excited about. I did live in Mississippi in the early 80's and do recall them on menus, ( I did not partake) but still kind of think of them as an unique creature worthy of observing. Here at home, my favorite creature (outdoors) is our toads, we have an extensive garden and pond area dedicated to just those creatures. Just because I don't know, where abouts in the U.S. do you reside? <In southern California, next to Mexico, a town called San Diego> Do you ever come north to Canada? <Yes, but not often... usually travel to places where the water is warmer... to dive, make photographs. Bob Fenner> Linda

"A Craw-Fish by any other Name would Chew Plants..." Mr. Fenner: I am in the early stages of preparation for building my first community tank. I am planning a 35-Gal tank with many live plants and two species of schooling middle fish, one species of surface fish, and an additional species of bottom-feeding/Pleco-type fish. Is this feasible? <Sure> My main concern is this: I feel that in the future I may be unable to defend myself against the irresistible charms of lobsters and crayfish.  <They are delicious... prepared properly!> Is there a place in a perfectly harmonic community tank for one of these invertebrates? <Mmm, no, not really. There are some fresh to brackish crustaceans that are "better"... please read: http://www.wetwebmedia.com/shrimpfw.htm> I hear that they have picky tastes in water pH and temperature, are destructive to aquatic landscaping, and can be determined to bust out and go AWOL. Is there a way to have fish AND yabbies? <Again... not really... their tastes are actually "too cosmopolitan", and many species are known to be quite "eury" condition... adaptable to widely varying conditions... but most all what folks call "lobsters", crayfish, crawdads, ditch "bugs"... are all too destructive, fish-eating to be "harmonious" in a community tank... Maybe two tanks? Bob Fenner> Please advise.

Caridina japonica and freshwater shrimp Hi Robert, I have some beard algae troubles in my tank and I want to ask you if there is any difference in purchasing C. japonica or any old freshwater shrimp? <Yes... very different animals. A bit on both on our site: http://wetwebmedia.com/shrimpfw.htm Bob Fenner> Keith

Freshwater Lobster <Lorenzo Gonzalez standing in for Bob-in-Asia> Hi, about three weeks ago I bought a blue freshwater lobster, and I know that it needs fairly hard water, do you know of any suitable tankmates for it? I hope that there are some hard water cichlids that will be suitable for it, but I'm not too bothered if they aren't cichlids. <Almost any Rift Lake Cichlid that won't get too big to eat it, and isn't too small to get eaten... will probably do fine. The larger S. American cichlids will happily eat the lobster, besides, most prefer softer water than their African relatives. Either way, most of these cichlids, and probably the lobster too, will likely be just fine with tapwater, if it isn't softened with a household softener (anathema to all fish, really)  -Lorenzo>

Ghost shrimp for trigger and puffer My fish love these things, but the LFS has problems getting them. What's it take to culture them? Thanks in advance. J -- <Really need to get to these sorts of pieces for articles, books and the websites... For now will tell you this can be done... and you may find the most information starting with the "Freshwater Crustaceans/Shrimps" section of the www.WetWebMedia.com site and the references beyond listed there (under Bibliography/Further Reading at the bottom of each article/section). Bob Fenner>   

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: