Antennal sense organs in the isopod Ligia oceanica (linn)

Abstract

The antennal tips of the isopod Ligia oceanica each bear approximately one hundred specialized sensory hairs. Their structure has been analysed by scanning and transmission electron microscopy and electrophysiological methods used to investigate some of their functions. Each hair has a double outer sheath protecting the inner structures which are only in contact with the external environment through a laterally placed sub‐terminal orifice. Internally the apical region contains numerous microtubular structures which are proximally associated with dendritic processes. From the hair base an extensive region of canals, also containing microtubules, is present. The cell bodies lie at the proximal end of the penultimate segment and have a few cilia associated with them. Each hair is singly innervated. Their mechanical function may aid this nocturnal animal to orientate itself when moving rapidly over uneven terrain. The chemical function may have some significance in species recognition and to testing the environment for noxious or desirable conditions.

Notes

Present address: School of Biological Sciences, James Cook University of North Queensland, Townsville, Queensland 4811, Australia.