Stress detection at the autotomy plane in the decapod crustacea

Abstract

Situated in the basi-ischiopodite of the brachyuran Carcinus maenas are two receptors which resemble the chordotonal receptors of the limb articulations but are obviously not part of the series associated with the joints. The receptors have large numbers of bipolar neurons with their dendrites embedded in distinct connective tissue strands which insert onto discrete areas of thin or soft cuticle. The receptor strands do not span a limb joint nor do they attach to a muscle or its tendon. The receptors are referred to as cuticular stress detectors (CSD). CSD.1 lies proximal to the preformed breakage plane and the area of cuticle onto which the strand inserts, lies close to the attachment of the anterior levator muscle tendon (autotomiser muscle). CSD.2 which lies distal to the breakage plane is located in the ventral ischiopodite.