The Sponge Crab, Domecia acanthophora, is a slow-moving scavenger that curiously attaches various anemones, sea flora, sponges, bryozoans, and coral polyps to its exoskelton in an attempt to camouflage itself. They are semi-aggressive and can harm smaller crabs or snails. Though generally stationary, it will move to eat and breed. The Sponge Crab is easy to maintain and thrives best in well-established reef tanks with a thick sandy bottom. Watching the Sponge Crab decorate itself is fascinating.