Hermit Crabs

[Tinman]

I have heard many a comment about hermit crabs in a reef aquarium, things like reef terrorists and the worst thing ever. Every LFS recommends them though, so I have to ask.
What's wrong with hermit crabs?

Thanks,

Mike

[leebca]

this question comes up quite often. First I'd like you to read these references to get your answers:
Aquarium Frontiers Library
Clean Up Crews - Reef Hobbyist Online Magazine

As crabs grow, they become more bold, beligerent and start eating whatever is available, including trying to catch and/or feast on sleeping fishes.

Lastly I would like to point out why LFSs recommend them. The LFS pays a couple of pennies for each of the common ones and sells them for up to $1. each.

There is a big profit in hermit crabs due to their availability, easy to catch, and ease of shipping/handling. Lastly, few die in the LFS tanks -- most are sold before they die, even the ones collected from the 'wrong' waters. These die in the hobbyist's tanks and then guess what? The hobbyist buys more.

[Ninong]

The number one reason people don't like hermit crabs in reef aquariums is that they will attack and kill snails for their shells. People who have deep sand beds in their reef aquariums also don't like the fact that hermit crabs prey on the beneficial microfauna that inhabit the top layer of the sand bed.

Hermit crabs may annoy some corals by simply walking all over them searching for food, especially flat corals such as Montipora.

Those are a few of the reasons that some people, especially reefkeepers with deep sand beds, prefer to limit or do without hermit crabs.