Interneurones in Crab Connectives (Carcinus Maenas (L.)): Directional Statocyst Fibres

Five interneurones in each connective respond directionally to rotation of a crab. Each seems to be activated by one direction of fluid flow in one statocyst canal. The anatomy of two is known and correlates well with a direct input from the receptors of one statocyst. Three of the fibres have input from leg joint proprioceptors. The swimming reflex and a complicated turning reflex are evoked on rotation of a minimally restrained crab. It is likely that the statocyst interneurones are involved in these and other behaviour patterns, including the rearing reflex and sideways walking.