Calappa Box Crabs? Seeking experience

[MantisShrimpMan]

Anyone have experience with crabs from the genus Calappa, aka, shame faced crabs, aka box crabs?

so: I’m from NY and I go to college in St Louis. While I was home from college on fall break, I went out clamming on Long Island. In quite the surprise, I found a box crab. They are by no means native to NY.

Now, we have our own ecosystems, but the gulf currents (especially during the summer) sweep up all sorts of unsuspecting fish. There’s a reef nearby me that consistently ends up hosting some butterflyfish, lion fish, seahorses, juvenile 4”barracudas, and more. Sad part is, most of those fish do not have the pelagic capabilities to work their way back south, and subsequently end up crab food as they do not have the ability to survive Northeast water temperatures during the winter. This would certainly be the same way.

I’ve always been interested in saltwater aquariums, so I used this as an impulse to set up my own. I set up a 20 gallon JBJ Cubey specifically for the little guy, and flew him back to STL with me. I like to think I saved its life . Anyways, he lost one leg in transport but is alive. That being said- I can’t seem to get him to eat! He found one of the two ledges I deliberately made where there’s a rock overhang over the sandbed, and he spends his entire days in that same spot, never moving more than an inch. I’ve been putting food, chopped up chunks of clam (also caught by me) in front of him, and despite this, he doesn’t move forward to eat it. Earlier today, I got worried and did something a bit silly, I took him out of the tank and while he was waving his claws, I jammed the clam in and put him back down gently. I saw his mouth flaps open and he probably took two or three bites before the rest of the clam drifted away.

That being said, this does not seem to have encouraged him to eat any further. I feel lucky that he has not died from osmotic shock, the chemical presences amidst cycling his tank, and a HORRIBLE experience flying him to STL on Southwest, but I don’t want to lose him to not eating.

also, can anyone help me figure out EXACTLY what species he is? I know the genus but not the species.

would love to hear from anyone with experience with this type of crab and getting it to eat.

 

[ISpeakForTheSeas]

Anyone have experience with crabs from the genus Calappa, aka, shame faced crabs, aka box crabs?

so: I’m from NY and I go to college in St Louis. While I was home from college on fall break, I went out clamming on Long Island. In quite the surprise, I found a box crab. They are by no means native to NY.

Now, we have our own ecosystems, but the gulf currents (especially during the summer) sweep up all sorts of unsuspecting fish. There’s a reef nearby me that consistently ends up hosting some butterflyfish, lion fish, seahorses, juvenile 4”barracudas, and more. Sad part is, most of those fish do not have the pelagic capabilities to work their way back south, and subsequently end up crab food as they do not have the ability to survive Northeast water temperatures during the winter. This would certainly be the same way.

I’ve always been interested in saltwater aquariums, so I used this as an impulse to set up my own. I set up a 20 gallon JBJ Cubey specifically for the little guy, and flew him back to STL with me. I like to think I saved its life . Anyways, he lost one leg in transport but is alive. That being said- I can’t seem to get him to eat! He found one of the two ledges I deliberately made where there’s a rock overhang over the sandbed, and he spends his entire days in that same spot, never moving more than an inch. I’ve been putting food, chopped up chunks of clam (also caught by me) in front of him, and despite this, he doesn’t move forward to eat it. Earlier today, I got worried and did something a bit silly, I took him out of the tank and while he was waving his claws, I jammed the clam in and put him back down gently. I saw his mouth flaps open and he probably took two or three bites before the rest of the clam drifted away.

That being said, this does not seem to have encouraged him to eat any further. I feel lucky that he has not died from osmotic shock, the chemical presences amidst cycling his tank, and a HORRIBLE experience flying him to STL on Southwest, but I don’t want to lose him to not eating.

also, can anyone help me figure out EXACTLY what species he is? I know the genus but not the species.

would love to hear from anyone with experience with this type of crab and getting it to eat.

With Calappa spp., some top-down photos of the crab's back (including some that show the portion of the shell by the crab's back legs) may be helpful with ID, and an ID may be important, as there are a few crabs that this one looks like it could be, and some of them are tropical while others are temperate. I'd say to add some pics of the shell from the top under white light (not enough to be blindingly reflective, but enough to light it up somewhat like it would be lit out at the beach), and another pic of the frontal view of the claws (like you have in your second pic above) - hopefully that'll be enough to help get a solid ID.

For the feeding, looking at a few different members of the genus, I'd say to try offering sea snails (I'd pick up a few live ones to offer it, but you can also find live or frozen, human food grade snails of a variety of species as well - olive snails, babylonian snails, conchs, whelks, etc. - and those may be good to try if it doesn't take the live ones you can get at your LFS or the frozen for if you don't want to be feeding live) and hermit crabs (I know at least one species eats Pagurus pollicaris, so if you have access to those, I'd try them, otherwise other Pagurus spp. or just whatever hermits you can get a hold that are smaller than the crab would probably be good to try).

Hopefully someone who has kept one of these guys will chime in for you here with better/more specific advice on keeping it, but that's the best I've got for now.