Swimming and the stockade: Defensive behaviors in the false arrow Crab, Metoporhaphis calcarata (Brachyura: Inachidae)

Abstract

I observed and obtained video footage of swimming behavior in Metoporhaphis calcarata. The behavior is described and illustrated by tracings of video stills over a one-second interval. The fifth pereiopods do not end in paddles, as do those of crabs in Portunidae, but rather are fringed with pinnate setae. On the sea floor, these crabs can form a "stockade" consisting of the acute rostrum and a circle of thorns on the distal surfaces of the pereiopods. © The Crustacean Society.