Need help identifying something.......

[jbfastlane]

Hey guys - need help identifying something in my tank. I have a crab like being that isn't one of the critters I purchased. It has two black with white dotted legs in front and blue-ish with red ringed legs otherwise.
Should I be concerned?? Is it a normal crab??
Thanks in advance - back to my mantis hunting!!!! Lost my percula last night. Over $100 in fish and cleaners now!!!!!!!!

 

[thomas712]

Sure that was a crab? He he could have been your mantis.
Thomas

 

[jbfastlane]

Please tell me you're making fun of me!!!!!!!!
Do Mantis live in shells??
I hear people laughing at me already..............

 

[thomas712]

Shrimp = exoskeleton = mantis next time grab him. I might be wrong but thats a pretty abby normal crab your talking about.
Thomas

 

[thomas712]

P.S. Don't grab him please use a net or something. A plastic lidded container would be good.
Thomas

 

[teatime]

Originally posted by jbfastlane
Do Mantis live in shells??............
If it lives in a shell it might be a hermit of some kind.

 

[rsd]

Is it a "true" crab or is it more like a HERMIT crab?
Have you SEEN the mantis or just finding half eaten fish?
If you have an abnormal crab, hermit or not, (size?) you may not have a mantis. It could be a hermit crab that eats fish. Not uncommon... not that common either. Any crustacean that I didn't buy ends up in my 'fuge or at the lfs unless I can positivly ID it.
Good luck.

 

[jbfastlane]

Thanks for the response - to clarify - I am losing whole fish - last night a 3" percula clown. And no pieces - parts - fins or lips to be found.
Before you say anything about lost in the rocks - I lost 8 fish ( 2 clowns, scooter blenny, 4 damsels and a psuedochromis). Not a spec of the corpse on any of them. Also I've lost 14 hermits (8 red-legs, 6 blue-legs), 2 peppermint shrimp and 8 turbo snails.
I have found the crab legs scattered around. Nothing else.
I figured about $120 bucks is sitting in a belly. Currently I have one yellow tang left and nowhere to put him. I have a trap with nylon and bait sitting in the tank. Can't find a LFS trap locally. Called XXX website and a very knowledgeable lady explained how to make the trap - said it was better than anything I might purchase.
I am totally vexed here. Ready to leave the few pretty rocks in the water and give up on fish. This sucks to be sure.
Thanks again for the advice.
Sign me - sitting in the dark waiting on the killer to return!!!!!!

 

[ags]

as far as identifying your crab I have no idea but in terms of losing all these fish without a trace of remains you might have a gorilla crab. Voracious predators that never stop. Will eat anything it can get its claws on. Although given the livestock you are missing you would have seen a molt some where in your tank by now. SOB's get big, fast. Just a suggestion. They look just like emerald crabs but cream colored with brown spots and hairy. Abundant in gulf rock.

 

[jbfastlane]

Hey Ags - I still have 2-3 crabs left. None are bigger than about a dime I-d say. How the heck can they catch a fish??? Crabs don't swim. The puzzling thing is my snails have been ravaged too. Thing is they hang out near the water level. What's going out an catching a fish - certainly not a crab???
At this point I am getting mad. Someone else suggested the following - any comments???
Make some water in a 5-gal bucket at around 1.035 salinity and soak the rocks one by one to flush out the critter. Of course the person was suggesting a mantis shrimp hiding in the rock.
Please keep the advise coming. So far the trap and bait idea isn't doing much.

 

[ags]

well first lets make sure what I suggested is the culprit. Do you have any crabs identical in body shape to an emerald with color markings similar to what I describe before?
If yes then more likely than not that is your culprit. Where did you buy your lr? If it came from the gulf coast waters of Florida you undoubtedly picked up a hitchhiker, or 3 or 4, of the gorilla crabs. Although that rock is also known to have a lot of mantis shrimp. And yes I have seen the gorilla crabs eat turbo snails right out of the shell. As for eating fish, they find where they sleep and ambush them. I have seen ones a little bit bigger than a nickel take out royal grammas.
But what you initially described is not a gorilla crab. If it carries a shell like a hermit crab then it is not a gorilla crab. If it is a mantis you should hear a clicking sound in your tank. The gorilla crab is a dull whitish brown with brown speckles and hair. Trust me if you saw it you would know. Looks very menacing.