where do hermit crabs get their shells from
Hermit crab Most species have long, spirally curved abdomens, which are soft, unlike the hard, calcified abdomens seen in related crustaceans. The vulnerable abdomen is protected from predators by a salvaged empty seashell carried by the hermit crab, into which its whole body can retract.[3] Most frequently, hermit crabs use the shells of sea snails (although the shells of bivalves and scaphopods and even hollow pieces of wood and stone are used by some species).[4] The tip of the hermit crab's abdomen is adapted to clasp strongly onto the columella of the snail shell.[5] Most hermit crabs are nocturnal.
Japanese spider crab The Japanese spider crab has the greatest leg span of any arthropod, reaching up to 5.5 metres (18 ft) from claw to claw.[5] The body may grow to a size of 40 cm (16 in) in carapace width and the whole crab can weigh up to 19 kilograms (42 lb)[6]—second only to the American lobster among all living arthropod species. The males have the longer chelipeds;[7] females have much shorter chelipeds, which are shorter than the following pair of legs.[8] Apart from its outstanding size, the Japanese spider crab differs from other crabs in a number of ways. The first pleopods of males are unusually twisted, and its larvae appear primitive.[1] The crab is orange, with white spots along the legs.[9] It is reported to have a gentle disposition, despite its ferocious appearance.[9] The Japanese name for this species is taka-ashi-gani literally translating to “tall legs crab.” Their armored exoskeletons help protect them from larger predators such as octopuses, but giant spider crabs also use camouflage. The crab's bumpy carapace blends into the rocky ocean floor. To further the illusion, a spider crab will adorn its shell with sponges and other animals.[10]