Yes Brett, I will give you that. If you want to keep a crab, Porcelains are ok.

The only crab I like is the porcelain. At this time I do not have any crabs in my system and its been that way for a few years. Back when I had blue leg hermits (2004?) I caught them picking all of the spines off of my large brittle star. It looked like a serpent star until I removed all of the crabs and the spines grew back. I once tried to add a single electric blue leg hermit to my display. It immediately went after a fighting conch so I had to remove it right away.

I also had a chalice frag go from this to the pic below because of a gorilla crab that was hiding out next to it. Once I removed the crab the chalice recovered to its former state.

http://i254.photobucket.com/albums/h...Picture697.jpg

http://i254.photobucket.com/albums/h...icture1238.jpg

Crabs killing stuff
 

Just a quick note to all those who say crabs kill snails and one another, its mostly because they want new shells! I had that problem and went an bought a handful of empty shells and put them behind my rock so it did not look bad in my display. Solved the problem as far as i can tell.

What about killing fish? Anybody think their crabs killed a fish?

Other than a few poached snails I've never had a problem with hermits. Though I will say that if anything happens to your tank and corals get stressed, blue legged hermit crabs will pick at the decomposing tissue and possibly prevent recovery/hasten demise.

I guess if you've got expensive shelled creatures that you really like and spent a lot of money on, they'd be something to be careful about. I've always looked at my snails as the vacuum cleaners of my tank and nothing more, so needing to replace a couple of nassarius snails every now and then doesn't really stress me out or lead me to think that crabs are bad.

I had several hitchhiker crabs come in on my rock, the big black ones with the hairy legs were supposed to be all evil or something. I never had a problem with them they were actually some of my favourite tank denizens.

I gave mine an assortment of shells of different shapes and sizes too... they still seem to like what the snails are wearing better. ;) I like having them in my tank though. My Zebra hermit crabs seem to be the most aggressive with snails and other hermit crabs.

+ 1 on the variety of types and sizes :)