Hermit crabs live inside empty snail shells in shallow water along beaches and in estuaries, small specimens on mudflats and large ones offshore. Some hermit crabs are entirely terrestrial, needing the water only to lay eggs. In the South Pacific, there are types that actually climb trees and very large ones that don't bother with a shell as adults.
The size of the crab determines what kind of shell, and upgrades are required as the crab grows. The Flat-Clawed Hermit Crab Pagurus arcuatus (right) is the largest in our area, and will often use Moon Snails and Whelks, but you will only find the big ones in deeper water. Small ones use Periwinkles and Oyster Drills.
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