From LiveAquaria site:
[The Spider Decorator Crab, also known as Camposcia Decorator Crab or Decorator Crab, is a member of the Majidae family of spider and decorator crabs. It decorates its brown body with sponges, shells, rocks, and other items as a method of camouflage.
It is nocturnal, hunting at night. In the reef aquarium, <u>it harvests algae, soft corals, and invertebrates to adorn its shell</u>. This activity may cause harm to some soft corals, but in the large reef aquarium, this activity actually helps spread and propagate these same corals throughout the aquarium.
The diet of the Spider Decorator Crab should include meaty foods such as chopped fish and clams.]
