Reef Discussion

[Ben Broadfoot]

We've lost a few fish recently, and found one fish we had for over a year (an always healthy bicolour blenny) in the claws of this crab. I know they're scavengers, but are they dangerous?

 

[lukusis]

Not sure on an ID of that one, but it is my understanding that anything hairy or that has black tips to its claws/black claws, is unwanted as is usually predatory in nature.

 

[Agent M]

It's possible, I'm not sure about the black tips on those claws for your particular one. My experience with the plain brown, hairy ones is that they leave everything alone but are opportunistic scavengers. If they get the chance, they will grab a fish, but usually the fish has to be sick or injured.

If you are losing fish, I would do a precautionary large water change before looking at the crab - that's how infrequently they tend to take fish IME.

 

[Ben Broadfoot]

Thanks guys. Yeah I've done big water changes. Ammonia, Nitrites are at unmeasurable levels, and the nitrates are very low too. I'll put the crab in my sump anyway.

 

[Agent M]

Yeah sump it. I quite like having little critters like that around - they are interesting to keep.

I guess its a bit like asking you "Have you tried turning it off and on again?" but as there are so many unknowns we don't test for in our tank, a water change remedies many situations. Sometimes something just isn't right despite what the tests are saying.