Red Claw Crab Missing Limbs   10/12/10
I purchased 2 Red Claw Crabs from PetSmart.
<Perisesarma bidens and interesting, if aggressive, brackish water crab.>
I believe one was male and one was female, do to the markings on their underbellies, plus one had slim claws, and the other had fat, wide claws.
<Do bear in mind males and females view each other as food except when mating!>
After about a month, one crab (female) molted. She was seemingly fine after the molt, with all appendages in tact. Two days later, 2 legs and both front claws were missing. I removed the other crab (male), assuming he attacked her. Three days later, the attacked crab died.
<As often happens.>
Am I correct in assuming the other crab attacked her?
<Possibly. When crabs moult they would normally hide in places such as caves or bury themselves in leaf litter. Either way they'd be out of view. Crabs view one another as potential meals, and in their "soft" state they're easy targets. A lot depends on their environment, and in a spacious tank with plenty of hiding places crabs can moult successfully. But if you crab two crabs in 5 or 10 gallon tank, it's hard for them to avoid each other, and if there aren't any good hiding places, and I mean REALLY good hiding places, not some upturned flowerpot, then they can, will attack one another.>
Did the molt have anything to do with what happened here?
<Can certainly be a factor. But bear in mind lack of iodine is a very common reason for failed moulting. Use marine aquarium iodine supplement at 50% the quoted dose per gallon of water. Also make sure their diet is calcium-rich -- a mix of whole lancefish, unshelled shrimp, and suitable soft fruits should do the trick, along with regular offerings of crustaceans foods such as those from JBL, Sera, and others.>
Would the lost appendages result in her death?
<Not in themselves, no, but lack of iodine can cause various problems, deformed appendages merely being the most obvious symptom.>
Also, I've read on your site that RCC are land crabs, but mine stayed in the water most of the time.
<Well, they are land animals. In the wild they live in estuaries, dipping into brackish or salt water periodically but foraging on land. On the other hand, for a variety of reasons they may prefer to stay underwater in a given aquarium, perhaps because there's only enough dry land for one dominant individual. Cold and dry air can also stress them.>
My tank set-up: 10 gallon tank, part land, part water. Sea salt mixture added to water,
<How much? You really need brackish water, not "teaspoon per gallon" amounts of salt. Use marine aquarium salt at not less than 6 grammes per litre (~3.8 US gallons), and ideally 9 grammes/litre, for a specific gravity of at least 1.003 and ideally 1.005 or more at 25 C.>
with calcium and other trace elements especially for invertebrates.
<Iodine is the key, and yes, you do need iodine supplement.>
Utilized a terrarium filter to clean the water. Fed spirulina flakes, bloodworms, krill, and crab pellets. No heater was used in the water.
<Well, that's one problem. They are tropical animals. The air needs to warm and moist. Essentially you're creating a habitat similar to what you would for tree frogs, except the bathing pool contains brackish rather than fresh water. Apart from that, the coconut fibre substrate will be similar, and the bogwood and plastic climbing branches will be similar.>
After this experience, I do not believe PetSmart should be selling these crabs.
<Difficult to argue against. But they are bizarre animals, and some dedicated individuals have even bred them! The larvae need to be moved into seawater conditions and fed tiny live foods, but it is possible.>
They seem to be aggressive towards one another,
<As are virtually all crabs.>
and their requirements go way beyond what the pet store would have you believe.
<Same with Goldfish, to be honest.>
I wouldn't recommend them as a pet for the average person.
<The huge problem is that the "average person" doesn't usually keep pet animals terribly well. How many dogs do you know that get short, infrequent walks? How many parrots do you know living in small cages? How many Goldfish do you know get in bowls or small aquaria? You and I are different in caring about how animals are maintained in the home; the average person often doesn't care all that much -- or perhaps more charitably, doesn't understand how badly they're treating their pets.>
Thank you for any information you can give! Your website is awesome!
<Kind of you to say so.>
Lorie Masi
<Cheers, Neale.> 

How long after treatment can crab go back into tank?  6/14/09
Hello Crew,
I had a fish showing signs of an intestinal parasite, so I dosed the tank with Jungle Labs Parasite Clear to try to save the one fish plus prevent the other fish in the tank from getting sick. The tank also housed a fiddler crab, which I removed to another tank prior to doing the treatment.
I will be changing 25 percent of the water and repeating the treatment in 2 days as per the instructions on the medication, then continuing normal water changes after that which is normally 20 percent twice a week. If necessary, however, I may change more than that immediately following the treatment. How long do you think it will be necessary to wait after treatment is completed before I can bring the crab back to the tank?
Thanks,
Joe
<Medications can be removed using carbon or better yet a product called Polyfilter, but if you do three 50% water changes, one per day, you should flush out pretty well all the medication in the tank. You can then add whatever invertebrates you want. Cheers, Neale.>

Red Claw Crab <Hi Anthony, MacL here. The only red claw crab I know of is actually a brackish crab often sold for freshwater. Is this what you have?> I purchased a red claw crab from a local Fish store about 2 weeks ago. I believe the crab is a female due to the very small claws.  Anyway, recently she has had her abdomen hanging open. <Maybe releasing eggs?> I figure she was getting ready to molt, but she hasn't done anything for 2 days now. She has already molted once since we have had her and it didn't take long.  She has plenty of different kinds of food.  Also these past 2 days she is flipping herself over on her back. <Not a really good sign.>  Can you tell me what is wrong? <I'm just guessing here but I think you probably have her in fresh water and she needs some salt. I also think it might be a difference in PH as well.>  I have searched through the internet, but cannot find any information on Red Claw Crabs.  <I did a search on Google and came up with tons of thing on them.  You might try www.google.com> Thank you for your time and patience. <Anthony you might do the research on them and decide if it needs to be in brackish water or not and make a decision from there.> Anthony <An excellent site re this species: http://wrongcrowd.com/aquaria/crab/ RMF>

Injured Red Claw Crab Hi, firstly thanks for such a great website! The information here is comprehensive yet easy to understand. Unfortunately I have a problem with my Sesarma bidens crab. The other night whilst cleaning out the tank I did not notice the crab (Colin) burrowed under a plant, as he is almost always hiding under an ornament on the other side of the tank during the day (or breathing sitting out of the water on top of it).  He just recently molted (about a week ago) so I thought I would leave him under the rock and clean the tank around him. Well I dumped the plant in a bucket (with Colin underneath it) and proceeded to vacuum out the gravel and remove other ornaments to the bucket. It was only when putting the ornaments back that I noticed Colin at the bottom of the bucket on his back... I immediately picked him up and put him in the tank but he didn't move, I put lots of little bits of food in front of him and left him for the night thinking the worst.  When I came back in the morning he was on his back again but when I went to lift him out of the tank assuming he was dead he started moving his legs frantically, anyway I righted him but noticed that 5 of his legs were not working as well as one claw (I think they must have been broken in the accident) he was attempting to move around but the legs were preventing him, I left him for the day came back and he still had not moved despite attempting to with his working legs, so I amputated 3 of the legs at the base (not the claw) he is now a lot more mobile however he is unbalanced due to missing 2 back legs (resulting in him overturning and not being able to right himself frequently/a few times a day).  I have also since noticed that one side of his mouth is not working (i.e. the exterior movable parts of his mouth that he uses to clean his eyes) he can still move it a little but cannot properly function.  My question is: Is there anything I can do for Colin? I am aware that crabs can regenerate limbs during a molt but has he just sustained too much damage? <I hope not> My main concern is his mouth as I cannot see whether he is eating properly. Would it be kinder to just kill him now or try to aid his recovery?  <I would not euthanize this animal. It may well recover> It has been three days since the accident and he is still defending his food against the fish (a few platies) but I cannot establish if he is eating the food or whether the platies are eventually managing to take it all. In this situation could a premature molt occur or could he partially grow back before a molt? <Not before, but might molt again sooner, shrink in body size> I really don't want to have to kill him but equally I do not want to prolong his life if he is suffering with very little chance of recovery. He is in a 5 gallon tank with 0 ammonia, 0 nitrites, 20ppm nitrate, just over 1 tbsp. of salt per gallon and I am lifting him out of the tank daily for a few minutes to allow him access to air. pH is 6.6 (low I know but I added dolomite to the filter on the day of to raise it so hopefully that will start to take effect). Should I dose with Iodine? <Yes, I would> Sorry for the long question but I am very concerned about him.  Thanks, Chris <Do take care to maintain good, consistent water quality, assure this animal is getting food. Could take weeks to a few months, but may well be fine. Bob Fenner>   

Thai devil Soapdish crab I know this is not truly an aquatic species, so I don't know if you  can help.  However, I thought that if you didn't know the answer, you may  know someone who does. <Mmm, am actually one of those "guilty" ex-retailers of yore who used to sell these w/o much knowledge of their husbandry> My friend has a Thai Devil crab (Soap dish crap).  His large  claw is inflamed at the joint where it attaches to his body.  He is in  a 10 gallon tank, partially filled with water.  He has land access and  spends most of his time there now.  He is still eating as normal and very  active.  The Ph of the water is 7.0, but she does not have any salt  added. <IS a freshwater animal, that DOES eat various meaty foods>   He is fed a varied diet of krill and hermit crab pellets.  She  soaks the krill in vitamins before she feeds them to him. <Good> I understand  that iodine is important to these crabs. <A essential micro-nutrient for much life, including you and I. I would add Lugol's solution, potassium iodide/iodate once a week or so... to this animals water.> Does he need special  lighting? <No> And could the inflammation be a sign of an impending molt?   <Maybe> He is full grown and they only molt once a year I think.  She is very concerned about his health, she has had him for about 6 months.  Any information would be greatly appreciated. Thanks, Caryn <I encourage you to place the above title words in your computer search tools and read what little there is posted on the Net re this crab/species. Bob Fenner> Fiddler Crabs, Ich Problems? Is there a safe medication to treat for ich that will not kill my fiddler crabs? <Yikes! Ryan here today.  We use a quarantine method to treat infected fish- That involves removing the infected animals, and treating them separately.  In that case, your crabs are safe!> It's been 20 years since I've had an aquarium, and it seems that many rules about keeping and caring for freshwater fish have changed.  <I'll say!> I did my homework and researched the subject so that I felt comfortable with my choices.  About 2 months ago I purchased a 55 gallon aquarium, and started with about 5 Neons to get the water cycle to do its thing.  I now have several fish: 5 swordtails, 6 mollies, 5 dwarf platies 6 dwarf Gouramis, a Pleco, 6 Cory catfish and 6 fiddler crabs.  (I love the fiddler crabs.) <That Pleco will soon outgrow the 55 gallon tank...I'd inquire early about trading him for a smaller Pleco once he's about 6 inches.> Everything was going well, including the birth of about 30 babies (black mollies, silver Lyretail mollies and sunset dwarf platies) until last weekend when I did a 25% water change to correct nitrate and total alkalinity levels.  I also rearranged the fake plants, rocks and log to allow the fish to have more swimming room and to ensure a better water flow from the filter.  I must have really stressed my poor fish.  The other day I noticed that 2 of my dwarf Gourami had small slits and little holes in their upper fins.  That evening I noticed my male silver Lyretail had trouble swimming and was at a 45 degree downward angle, and sometimes faced straight down.  I immediately added extra aquarium salt to the tank and increased the water temp to 82 degrees (from 78).  The following day, after work, I purchased a 6 gallon  'hospital tank', Maracyn and Maracyn-Two for my 3 sick fish.  Unfortunately, when I got home, one of the Gourami had died.  It looked to be sick for only 24 hours, so I was pretty shocked to find it dead that quickly.   I checked all my fish and decided that only 2 of the other Gourami had what is probably Fin and Tail Rot, so I put them, along with my male Molly into the hospital tank, using water from the 55 gallon tank.  (I didn't want to stress them further.)  I've been medicating them for 3 days now and they are looking much better.  My Molly is actually starting to swim somewhat normally, so I believe there is hope for him. <Sounds hopeful!> Now for the bad part... I came home from work today and found 3 more fish in the 55 gallon tank that look like they have Fin and Tail Rot.  It also looks like there may be a white spot or two on these same fish.  I have CopperSafe that I was going to use in the hospital tank if I needed to treat for Ich, but I can't use it in my 55 gallon tank as it would kill my crabs.  I've started treating the big tank for Fin and Tail Rot, but am not sure what to do about the possible ich, as I don't want to kill my crabs. <You're going to need to treat all infected fish in the QT tank.  Next time, add the fish to the display tank AFTER they have successfully completed 6 weeks of quarantine.  Then you won't have the same issues.  This time around, it's the long road my friend.  The answer to your question is no- There is no ICH treatment that is truly crab-safe.  Good luck, Ryan> Chris

Crab Questions - 04/15/2004  Hello Crew-  <Hello, Jessica!>  First of all, I wanted to tell you how much I've learned from your website on the subject of my newly purchased Sesarma bidens! However, I do have a couple of questions for you, and I know you can help.  <Whew, you're a lot more confidant than I am! But I'll try my best.>  I have a 10gal. freshwater tank for the two crabs I purchased close to two months ago. Both of the "girls", my 12 year-old son lovingly named "Tara" & "Melissa", have been doing wonderfully. They both have been eating well on a diet of algae pellets and shrimp pellets.  <So far, so good.>  But, after checking them both yesterday morning, and then later that afternoon, I discovered "Melissa" was in a normal up-right position, but wasn't moving at all. Maybe I'm being very ignorant and naive, but I didn't want to throw her out until I knew for sure that she wasn't actually dead and could be molting.  <No, I understand. Though, the molting process is usually relatively quick, and they'll usually hide while they molt, and while their new shell hardens.>  I did check her this morning and there's still no movement. I've spent the last three hours culling through information about the crabs, but I've had no luck in finding anything on what a dead crab will look like compared to a molting crab.  <At this point, if she's not moving, I would pretty much suspect the worst. I am very sorry. It may have been aggression from the other crab; this species, like quite a few others, are pretty aggressive with one another.>  We owned a very large hermit crab for five years, so I am very familiar with molting. But I've never owned crabs before.  <They're pretty much the same.... Though I would add iodine to the water (see our shrimp & invert FAQs for details), and would certainly allow them a space where they can get out onto a dry space somewhere in the aquarium; it is quite crucial that they have a land space.>  I also wanted to ask about the actual necessity for salt in the water for these crabs.  <It is unnecessary. They may do somewhat better in brackish water, and certainly need high-end brackish to breed, but should do quite well in freshwater.>  I found a ratio of 1tsp/10gal of kosher salt...it this a correct and safe figure to go with,  <Yes, certainly. You'll still be "fresh" water, essentially. Even salt-sensitive fish can tolerate this concentration.>  and will it hurt goldfish if I choose to put them in the water too?  <The salt would certainly be fine for the goldies - BUT - ten gallons is really far too small for goldfish. I would recommend something simpler in terms of maintenance; goldfish are really far too messy of waste producers to keep in such small confines. How about mollies? These would do exceptionally well, you could keep a few in a ten gallon with the crab, and bring up the salinity, even to full saltwater, if you desired.>  Thank you so much, and I hope to hear from you soon. Jessica Linaweaver  <You are quite welcome; thank you for writing in. Please let us know if you have any further questions! Wishing you and your crab well, -Sabrina>

Legless Fiddler - 03/27/2004 Any idea how long it takes a fiddler crab to regrow its legs?   <A few to several molts, I would assume.> I have one that lost all but 1 leg and has his 2 pincers still (poor guy)   <Poor guy, indeed!  Yowch!> someone is obviously nipping at him, but haven't figured out who since I have so many other inverts.   <Yikes, that's no good.  He won't recover unless you separate him from whatever's hurting him.  He really needs a separate tank to allow him recovery time.  If you like, you can let us know what all you have in your tank, and how big the tank is, and we can try to figure out who the aggressor is.> Anyway, any idea how long till the poor guy gets his legs back?    <Feed him plenty, and be sure to add iodine to his tank, if you don't already.  This will help him as he molts to produce a good quality exoskeleton.> Thanks!  Jennifer Schelfhout,  Palatine, IL <You bet.  Wishing you and your crab well,  -Sabrina>

Land Crab Sickness  - 3/7/07 Hi, thank you for taking the time to read this.   <Thank you for taking the time to send it!> I have what the pet store called a Halloween Land Crab.   <Ah!  Gecarcinus sp., maybe G. lateralis.> He is not set up in some amazing aquarium, he is just in a plastic cage.   <Really better if he has a slightly damp sandy substrate deep enough to burrow in and sufficient water to completely submerge himself; preferably both a container freshwater and a container of saltwater.> I have a water dish for him that's 2 inches deep that he climbs in and out of.   <As long as he can completely submerge himself, this is okay.> The bottom of the cage is filled with calcium sand and aquarium pebbles.   <Moist, I hope?  And deep enough to burrow in?> He has been doing really well eating bits of fruit such as apples, oranges, pineapple and also an occasional guppy. <He'd do better to have a little more "meaty" food in his diet - bits of human-consumption shrimp (frozen then thawed, uncooked, preferably including the tail or shell), krill, etc.> But recently three of his legs fell off on his right side!  What is going on? <Possibly a calcium and/or iodine deficiency....  A diet containing more of these nutrients is important.  In crabs that are more aquatic, supplementing their water with these nutrients is very helpful, but in your more land-dwelling Gecarcinus, I don't think it would be beneficial enough to do so.> He was not in a fight with another crab and I've never experienced him going through the "shedding process"! Is he unhappy or sick? <More likely sick, I'm afraid.> How can I tell what's going on? <That's a tough question with no easy answer.  Unfortunately, there isn't much information about invertebrate disease.  The best we can do for them is to provide them the closest environment to their natural habitat that we can provide.  In the case of your crab, this means HIGH humidity, substrate to burrow in, and enough water to totally submerge itself when necessary.  I would fear that perhaps the humidity is the problem in this case, as you mention that he's in a very basic setup.  A 10 gallon tank or larger with a lid to help keep in humidity would be very good in this case.> If this is below what you guys do, then I'm sorry to waste your time, <There are no questions that are "below" us.  Your crab is important enough for you to write in, so it's important enough to us to help you!> I just need simple answers and can't seem to find them anywhere. <There are no simple answers with invertebrate pets, my friend.  I wish there were.  Try providing him a more humid environment and a diet with more iodine and calcium (again, shrimp with shells, krill - these will be helpful!) will likely be the best things you can do for him right now.> Nick <All the best to you,  -Sabrina>

Halloween Land Crab 03/17/07 Hi, thank you for taking the time to read this.  I have what the pet store called a Halloween Land Crab.   <Gercarcinus sp., maybe G. lateralis.> He is not set up in some amazing aquarium, he is just in a plastic cage.  I have a water dish for him that's 2 inches deep that he climbs in and out of.  The bottom of the cage is filled with calcium sand and aquarium pebbles.   <Ideally, he needs a sand substrate deep enough and just damp enough to burrow into, and needs enough saltwater and enough freshwater, each in separate containers, deep enough to fully submerge himself - though the land area is by far the most important.> He has been doing really well eating bits of fruit such as apples, oranges, pineapple and also an occasional guppy. <Needs more meaty foods, preferably things like human-consumption shrimp (raw, frozen and then thawed) and fish; krill, meaty fish foods, and also Nori (seaweed) would be other important foods.> But recently three of his legs fell off on his right side!  What is going on? <Likely he is very deficient in something that he needs - saltwater, perhaps, or iodine....  Feeding the foods mentioned above, especially shrimp, krill, and Nori which are rich in iodine, will be very important.  Supplementing the food with a reptile calcium supplement will be helpful, as well.> He was not in a fight with another crab and I've never experienced him going through the "shedding process"! Is he unhappy or sick? How can I tell what's going on? <sounds like a state of disease, not a normal molting situation at all....  I would urge you to improve this critter's living space and food.> If this is below what you guys do, then I'm sorry to waste your time, <A question is never a waste of time.> I just need simple answers and can't seem to find them anywhere. <Thank you very much for searching for your answers, and for asking questions.> Nick <All the best to you,  -Sabrina>