The morphology and ultrastructure of tension receptors in the walking legs of the crab, Carcinus maenas.

The tension receptor system of the crab merus consists of two size classes of receptor cell body distributed along one face of the flexor muscle apodeme. The receptors show the general arthropod mechanoreceptor structure of cell body, connecting cilium, and sheathed sensory processes, but there are several differences. Many processes show convolutions, and the distal portion of the sensory process is embedded in the apodeme cuticle. The terminations of the sensory processes lack the usual structural specialisations for mechanotransduction. Tension transduction appears to occur by flexion of the cuticle-embedded sensory process.