Most species are marine, but some tropical forms, such as the coconut, or robber, crab, Birgus latro, are largely terrestrial. This species, the largest hermit crab, has a body that may reach 16 in. (40 cm) in length, with legs that span 3 ft (.91 m) or more. It becomes increasingly terrestrial and develops heavy armor as it matures into an adult, at which stage it is able to completely discard its adopted shell. With its great pincers it has been known to crack coconuts, which it obtains by climbing palm trees. Coconut crabs also have been observed preying on birds as large as a booby.
Hermit crabs are classified in the phylum Arthropoda, subphylum Crustacea, order Decapoda.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
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