Hermit Crab
Hermit crab (Pagurus lanuginosus, family: Paguridae) is an omnivorous marine animal that utilizes shells for the protection of its abdomen. When it is attacked by predators, it withdraws its body in the shell and defends itself by firmly clinging to the shell by fourth and fifth pereopods, and blocks the hands of predators by the right cheliped.
Pagurus lanuginsus
March 2003, Tokyo Bay, Japan
The photo shows the lateral view of a hermit crab (Pagurus lanuginosus). The body structure of Anomura is somewhat asymmetrical. The abdomen, which is normally protected by the shell, winds clockwise where pleopods are attached on one sidef. The right cheliped is larger than the left cheliped. The cheliped carries a pair of movable and immovable fingers. Its cephalothorax is covered with anterior and posterior carapaces. The anterior carapace is hard whereas the posterior carapace is soft and covers the gills underneath.
The photo shows the dorsal view of the hermit crab. The five pairs of legs are shown in the photo (Decapoda, ten legs). The red-orange antenna is characteristic feature of this species (Pagurus lanuginosus).
The photo shows the ventral view of the hermit crab (male). The abdomen is soft and covered by thin membrane. At the end of the abdomen, a pair of uropods function as an anchor that hangs on the shell.
The mouth is located between the pairs of maxillipeds. There are three pairs of maxillipeds.
January 2004, Chiba, Japan