Dardanus megistos
"The White-spotted Hermit Crab, also referred to as the Red Hermit Crab, has hairy red legs with black-edged white dots. It has unequal-sized claws (the left one is larger) which it will use to catch food. It lives inside empty gastropod shells.
The White-spotted Hermit Crab is not safe for a reef aquarium because it will eat tube worms, mollusks, and fish. It will also eat algae. In a community tank, however, it will keep the sand sifted with its constant search for food. It is best to keep just one specimen per tank, since it is aggressive towards other Hermit Crabs. As the Hermit Crab grows, it will need larger shells to inhabit. It is most active at night. It is a very hardy animal, and an interesting addition to an aquarium. If there is insufficient algae, the diet should be supplemented with dried seaweed, tablet foods, and earthworms. "