An unusual mechanosensitive cell in a crustacean exteroceptor

The ultrastructure and mechanosensitivity of a sensory organ in a terrestrial isopod are investigated. The mechanosensitivity of this sensory organ is demonstrated. Seven sensory cells are observed; one of them displays unusual ultrastructural features, a lamellar ciliary root and a tubular body‐like structure. The six other sensory cells are similar to usual chemosensitive cells. No sensory cell presents the characteristic cytological features of crustacean mechanosensitive exteroceptors.