Colored Sponge Crab

Sponge crabs take decorator-crab behavior to its logical extreme — instead of scattering bits of algae and debris across its shell, this crab cuts a living sponge down to size with its claws and holds the whole piece in place on its back using a pair of rear legs modified specifically into hooks for that one job. The sponge keeps growing over time, slowly molding itself to the crab's shape, so the disguise actually improves with age instead of needing to be rebuilt.

Care level: Easy · Temperament: Peaceful · Max size: ~2" · Min tank: 20 gal · Reef safe: Yes · Diet: Omnivore, scavenger