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FAQs about Crustaceans 3

Related FAQs: Crustaceans 1, Crustaceans 2, Crustacean Identification, Crustacean Selection, Crustacean Behavior, Crustacean Compatibility, Crustacean Systems, Crustacean Feeding, Crustacean Disease, Crustacean Reproduction, Micro-Crustaceans, Amphipods, Copepods, Mysids, Brine ShrimpHermit Crabs, Shrimps, Cleaner Shrimps, Banded Coral Shrimp, Mantis Shrimp, Anemone Eating ShrimpHorseshoe Crabs

Related Articles: CrustaceansMicro-Crustaceans, Amphipods, Copepods, Mysids, Isopods, Shrimps, Coral Banded Shrimp, Cleaner ShrimpP. holthuisi Pix, Mantis "Shrimp", Lobsters, Slipper Lobsters, Hermit Crabs, Squat Lobsters, Crabs, Arthropods, Pycnogonids (Sea Spiders),

salt water hermit crabs... gen.   8/20/09
Looks like you guys no how to take care of just about anything. So...Just got back from Padre Island
<Oh! I was there a few weeks ago... hiked out on the jetty...>
and the harmless shells my son brought home have hermit crabs in them.
They were found in the bay, not sure how salty.
<Variable, but ultimately full strength>
So how should I prepare the water, (since I'm not sure of the salinity).
How fast do I need to get them in saltwater since I live an hour from a pet store and can't get there today.
Thank you for your help
<Much to relate, learn... Read here:
and the linked files above. Bob Fenner>

Re: Crab Limb Autotomy Due to Environmental Stress as a Survival Strategy? 05/11/08 Hello Sara, Thank you for your quick response. I had read about crab limb autotomy as a _symptom_ of environmental stress on your (great) website. But why does the symptom exist? <Likely lack of nutrients/minerals/etc. needed to maintain the limbs.> My question comes from the presupposition that a trait exists because it gives the creature an increased chance to procreate. <Hmmm... sometimes traits exist for this purpose, but certainly not in every instance. Humans can lose limbs from anything from Diabetes to snake bites. These are certainly not traits which exist for the purpose of procreation!> I was hoping there was a reason like, "When a sudden change in the environment occurs, a crab with nine legs, who moments before had 10, stands a better chance to reproduce because …." <I highly doubt there is any such reason.> And here is where I lose it. I can't think of why this would be so. <Neither can I. Again, in the case of limb lose in poor environments, this is likely an illness rather than a "trait." Perhaps, the same stress reaction that results in limb loss to avoid capture, results in limb loss in poor conditions (both are sources of high stress).> I suspect it is not a strategy used to survive environmental stress. Rather, environmental stress produces in the crab the same sensations (similar stress level?) <Yep, this would be my educated guess.> as being in a losing battle, so he drops a leg. Anthropomorphizing a bit (OK, a LOT), I visualize the poor crab in a smoke filled room (from a fire), holding his breath with his eyes tightly shut until he can't hold it any longer - he ejects a limb. <Haha, ok.> I would appreciate any thought you might have. <I agree with your idea that both situations are stressful and that perhaps it's the stress reaction that results in the limb loss. Would you recommend a Japanese spider crab for my micro-reef? Just joking. <lol :-P> Thanks again. You guys are the best! Scott Allen Rauch <Thank you writing, Sara M.>

Crustacean Eyestalks  1/17/07 Greetings Bob ? I am the author of an environmentally correct children's guide to exploring the seashore entitled Seashells in My Pocket, published by Appalachian Mountain Club Books. I am currently working on the manuscript for the third edition, due out in Jan., 2008, and want to add a reference to eyestalks, specifically on lobsters and crabs. Can you answer a few basic questions for me? <Sure> Do all crustaceans have eyestalks? <Mmm... no. There are juvenile forms that lack these... and even blind/eye-less species> If not, do all crabs have eyestalks? <As far as I'm aware, yes> Does the length of the eyestalks vary much between species? <Yes... there are some with much shorter/longer...> Can all crustaceans that have eyestalks move them similarly? <Again... I do think so. Muscular... though there may be some structural, locking mechanisms as well> How would you describe the manner and degree to which they can move their eyestalks? <Can rotate to a wide degree left/right, up/down... around as far as the carapace will allow> Is there a web site that would have all this information (clearly and simply stated)? <Not that I know of... You have Robert (and Betty) Barnes... Buchsbaum et al. references?> I?ve been Googling for 2 hours! Thank you so much. Judith Hansen <Welcome. Bob Fenner>

Stripey the Hermit Crab 7/30/05 Stripey the Hermit Crab crawled out of his shell today - not his exoskeleton but his shell - he seems to be dead - he was moving around just a few minutes before this - there were other shells in the tank for him to crawl into - what could have happened? <You didn't read... on WWM... re Hermit Crabs... go there. Bob Fenner> Handle with Care (Crustacean handling) Hello! <Hi there, Scott F. here with you.> I would like to get a horseshoe crab and a purple reef lobster. I would like to know if it is possible to take them out of the tank and hold them? <Well, a horseshoe crab and a purple reef lobster are not like a dog or hamster.  I think excessive handling of any marine animal is not in their best interest.  I suppose you could pick the animal up once in a while, but the potential for stress and/or injury is too great.  Better to just observe through the glass of an aquarium.> Also, what aggressive fish would be compatible with them? Thanks. <Hmm...aggressive fish.  Another tough question.  Any fish tough enough to hang with a purple lobster is also tough enough to utilize it as a potential menu, IMO.  i.e. triggers, puffers, etc.  Best to enjoy these animals in a dedicated aquarium.  Best of luck to you.  Regards, Scott F.> Purple People Eaters- Or Harmless Amphipods? I have a 72g with 100lbs of LR, 6 inc DSB, 4 x 65W PC's, sump, skimmer and overall good filtration and circulation. It has been up and running for about 5 months now, and I have successfully cared for 2 Green Chromis, 1 Yellow Tang, 1 Ocellaris Clown, various snails and hermits. Lately, I have noticed little bright blue/purple "bugs" on the live rock, and they seem to be spreading. They are about half the size of common ants at biggest, most being smaller. They move around quite a bit and congregate together in groups. I've looked through the FAQ's and some books and haven't seen any real match's as to what they may be. My digital camera is broken which keeps me from uploading a picture. Any ideas as to what these may be? Thanks, Brian <Hmm...Sounds to me like some form of amphipods of some sort. Probably harmless, but a picture would really help us to make a positive ID for you...When the camera is up and running, do shoot us a pic! Thanks! Regards, Scott F>

Need advice for my PhD thesis <somebody write the Cliff's notes to "Reef Invertebrates"> hi guys, <howdy!> I am a grad student in molecular biology at UC Berkeley and I want to develop a crustacean as a new model system for studying developmental evolution.   <kudos for your educational ambition/endeavors> A few crustaceans are already being studied (Artemia, daphnia, Parhyale hawaiiensis) but they all have certain problems which keep them from being ideal.  The first consideration when trying to come up with a new animal to study is that it will readily reproduce in captivity... this is where you guys come in.  Ideally, I am looking for animals that can be kept in large groups without killing one another, who don't need coaxing to reproduce (the more they do, the better), and whose husbandry (especially of the young) is not overwhelmingly demanding.  Finally, an animal which matures quickly to breeding age would be good.  Oh, and as a final thought, the development of smaller guys like amphipods seems to be rather atypical when compared to most other arthropods, so I'm thinking something like a Lysmata or other shrimp or maybe crab might better represent the group.   <you were right the first time... shrimp. Much better understood, studied and viable for culture. Most crabs are very challenging to culture> I realize that I'm asking for quite a lot from one animal, and any info you guys can give me here would be very much appreciated.  Also, if there is anybody else you can think of who knows about captive breeding of crustaceans, I would love to be able to contact them as well in order to get more opinions.  Thanks a lot guys; I am a big fan of the site and I'm humbled by the amount of information you have compiled here. many thanks,-Mario <the genus Lysmata is very well studied. There is even a handbook for husbandry with a very popular species in the genus. Do seek "How to train and raise Peppermint shrimp" by April Kirkendall. As I recall, David Cripe of Monterey Bay Aquarium has Teamed up with Dr Rob Toonen of HI university to do a paper on the California peppermint Lysmata. Do search the archives at Scripps if you have academic access... I suspect you will find a remarkable amount of info on this wonderful genus. Anthony>

What are those little bugs? (2/24/04) Hi, <Howdy. Steve Allen here>   I hope you have the answer. <I'll try.>  We have a 55 gal. saltwater that has been set up for about 5 months.  All our fish are well, level readings are normal.  Problem is what appears to be lice like parasites on the walls of the tank. <Probably not parasites.> Are they a danger to our fish and how should we treat them. <Most likely no danger at all. If they swim/crawl around, they are almost certainly harmless (actually beneficial) mini-crustaceans known as copepods. "Fish lice" are isopods that hang directly on fish. If they appear to be attached to the wall, they may be some sort of harmless marine worm.>  We also noticed larger white parasites that appear to be snail like with a fan tail, also on the walls of the tank. <Do they move? May actually be a mini featherduster worm.> Any advice would be appreciated. <None of these are likely harmful. Enjoy the diversity of life in your tank. Read here to be more certain: http://www.wetwebmedia.com/invertidfaq4.htm http://saltaquarium.about.com/cs/pestscopepods/a/aa061200.htm http://www.wetwebmedia.com/copepodfaqs.htm http://www.rshimek.com/Invertebrate%20Key%20to%20Major%20Taxa.htm >   Thank you. <Hope this helps.>

Lopez and His Dicky Leg - He Shall Live! >Thanks Marina, >>My pleasure, Andy. >Lopez seems to have settled right back into his old ways, eating and walking about just as before, so I am probably going to leave him as he is. >>If this is the case, then I see no reason to mess about with him. >But if for any reason it begins to look like he'd be better off without the dicky leg, I now feel a lot better about the whole thing and think I could just about do it. Thanks again for helping me (and Lopez) out.  All the best, Andy (and Lopez) >>Heh, you're quite welcome, Andy, and as I said, it's my pleasure.  Marina Lopez May Lose His Dicky Leg >Ps....I have sent away for Kent Iodine, and will use a drop as you suggest.  Andy >>It may help, but I believe that some testing/research may be in order before you go fiddling with it.  As I said, seafood from crustaceans should provide some iodine as well.  Marina

Nuisance crab and worm Hello <Hi. Steve Allen here tonight> I have started a new 55 gallon reef tank. Its been up and running for just under a month. After adding my live rock I happened to notice a number of what I suspect are bristle worms. The problem is in one piece of live rock there was a very large worm. It's length was approximately 3 to 4 inches and that was the part sticking out of the rock. Since my attention has been drawn to this large piece of rock I have noticed that there is a good sized crab living within and under it. I haven't been able to identify it yet but when I shine a pen light into one of the holes in the rock I can see that its quit large. In any event I want both of these creatures gone. <A bristle worm of this size is not really a problem. Read through the bristleworm FAQs before you commit to getting rid of it.> I have tried trapping the worm by wrapping brine shrimp in a weighted nylon stocking, but that has failed. <There are better ways. Check the FAQs.> My question is since this tank is still so new, can I remove the rock and try extracting these creatures? I have heard that I could run the rock under fresh water and the worms and crab will exit and I have heard that I could submerge the rock in a high salt content water and they will vacate. <Number 2 is the better way to go. SG >1.030 > What would your suggestions be? I have also attached the tank log for your inspection <nice log. Do you have Excel? A spreadsheet is a nice way to track/trend your parameters.> thank you for the help <Hope this helps.>

Who Will Win the Shrimp War. I'll bet on the Mantis (12/10/03) Saludos Salados: <Greetings> Last week I purchased a CBS and placed him on a 10gal tank. This tank has been running for a year with no apparent problem. The other tankmates are a Cinnamon Clown a Turbo snail and a couple of Bumble Bee snails. Recently my wife noticed  a strange animal in one of the life rock holes. For her description I think we have a Mantis in the tank. <Uh oh> This would explain the disappearance of a Royal Gramma about a month ago. <Quite possible.> My question is, will the CBS kill the Mantis or the other way around? <I'd put my money on the Mantis any day. It has a much more formidable weapon> I am concerned for the CBS (named Jacques) which my son regards as a cool pet to have. <CBS are way cool. I love mine. Do get rid of that mantis. Start here: http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisfaqs.htm> Best Regards; Jos?A. Gonz?ez

- What is this Noise? - I guess I either have a mantis or pistol shrimp.  Here is my question...   I have not added anything to my tank besides new water and supplements for over a year.  However, last night I heard a click or tap noise.  One tap, then 4-5 min of quiet, then 1 or 2 taps then 4-5 min of quiet.  This went on for a few hours. <Sounds like a snapping/pistol shrimp to me.> I can't see in the corner very well cause of the coralline on the backside glass.  I've read where people have had this after adding some new LR, but a year later? <Sure, such things can arrive in a planktonic stage and take a while to develop.> So far, I haven't noticed any deaths of my livestock.  I haven't seen any moltings floating around either (which I'll often see from my other shrimp and crabs).  Would you still think this could be what I have? <Yes, snapping shrimp are perhaps the most numerous crustaceans on the reef - often when diving you can hear a constant din of clicks with little or no interruption, but you rarely see the source of the noise. Many Alpheids are very small and stay well out of sight - the only chance to know they are there is when they deploy their specialized claw to pop an amphipod or similar piece of food. No worries.> Thanks for your help as always. Neil <Cheers, J -- >

Crustacean Compatibility >Hello All, >>Hello one. >Thanks for all your great advice. >>I haven't given it yet! >I have a question about adding shrimp to my 75G, for now fowler tank w/80 lbs live rock.   My original plan was to add one each: scarlet cleaner peppermint coral banded After searching the FAQs I have crossed the coral banded shrimp off my list. >>Smart move. >I would like to know if 1 cleaner and 2 peppermint could coexist in this system.  I do have a few Aiptasia, so I would like to try the peppermint. >>Absolutely!  However, do be CERTAIN that you get Lysmata wurdemanni, and don't feed them too copiously or it's likely they'll simply ignore the Aiptasia. >Also, would like to see if the cleaner would service my fish. >>It's more likely a few neon gobies would do this, but a cleaner would not hurt at all.  If nothing else, I know they'll try to service you (if you'll let 'em). >I have the following species: 1 yellow tail damsel 1 yellow tang 2 false perculas 1 royal Gramma 3 green Chromis >>I think the only fish the cleaner shrimp would have any success with would be the tang, once it's around 3"-4". >Thanks in advance for your expert advice, Jeff >>Heh.. hardly expert, but you're welcome anyway!  Marina

Baby Shrimp? 9/23/03 I have a shrimp (Lysmata amboinensis) in my tank for about 5 months. I have only had a single shrimp in my tank. and I was thinking about getting a mate for it. but while feeding frozen food to the tank today I noticed small creatures under the rock jumping like kangaroos and running around. upon closer inspection I saw that they look like the shrimp I have, the biggest ones are about 2-3mm with other small ones. they are only under the rocks and hides when I shine the flashlight on them. I am not sure if they are really shrimps though. can a shrimp lay eggs and fertilize it on its own? if they are shrimps then how can I take care of these little creatures. thanks for any help you can give me in this regards. <the creatures you are seeing are almost certainly zooplankton - microcrustaceans like Amphipods or Mysid shrimp. They are not likely to be baby Lysmata, although they may look similar. They are quite beneficial nonetheless. Best regards, Anthony>

Baby Shrimps II 9/24/03 how can I differentiate between Mysid shrimp and baby Lysmata? <we could find pictures of larva on the Web... but please take my experienced advice here, mate... parthenogenesis (the sort of "virgin birth" or non-fertilized egg development) is very uncommon. And Every tank with live rock or live sand has almost certainly got common microcrustaceans like mysids> the small ones look like the replica of the big shrimp. the tail matches the shape of the big shrimp. <the larvae of many arthropod kin look quite similar> (I am not talking about the color though) they have no color. I'll send a pic if possible during the weekend. And can a Lysmata fertilize its own egg if it is the only shrimp in the tank. <self-fertilization is very rare, even among asexual critter like your cleaner shrimp> And you said beneficial...........do you mean as food for other organisms in the tank? ok thanks. <mysids and other micro-crusties are beneficial as scavengers and as a food source for fish and other inverts... do check out our new book Reef Invertebrates on the subject. We have a chapter on microcrustaceans in it... and pics throughout of such creatures (see page 301). Kind regards, Anthony Calfo>

Clicking noise at night I have 2 questions. I'm very new to keeping a marine aquarium. I've had my aquarium a bit over 2 months now. My aquarium is 180litres and has live rock and coral etc. and at night I can hear a clicking sound.<could be a mantis or a pistol shrimp> Someone told me that this is a shrimp that eats little fish if you don't feed it properly.<it could be> Is this true? What is the clicking noise and can it be a hazard. If so how do I get rid of it?<if it is a mantis shrimp, you might have to remove it. depending on the size of your fish. though many mantis shrimp grow to about an inch and are pretty much harmless. unless you have inverts I would get rid of this shrimp, just in case. purchase a mantis trap or search the internet. some people have unique ways of catching these stomatopods.)> The fish in my aquarium include, 2 green Chromises, 2 yellow tailed damsels, 2 clownfish (allardi), 1 yellow tang, and 1 coral beauty. When I first added my fish I put a semicircular (Koran) angel fish and a bicolour angel but the semicircular killed the bicolour angel and when I put in the coral beauty I think the coral beauty killed the semicircular. Does this mean I can't keep 2 angelfish at a time?<yeah it does!!> What is your suggestion on my next fish? <I think your pretty much stocked. but you could go with another small wrasse maybe from the genus Pseudocheilinus>Also the fish are very small at the moment and what will happen when they grow because my fish tank is very small? <you will have to purchase another aquarium or get rid of the fish...or they will eventually perish, good luck, IanB> Thanx Sarah

Marine Micro-crustaceans 7/13/03 Anthony-I have a 40 gal sump for my reef tank there is nothing but water and a heater in it. The bottom is cover with coralline algae. Also there is what looks like some underwater ants on the bottom, are they good for the tank or should I clean them out.    Linda Gibson  Ralph wife <the ant-like creatures you have observed are very beneficial micro-crustaceans (plankton) and serve as food and scavengers for the tank. Very desirable. Kindly, Anthony>

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