Hydrodynamic and Acoustic Field Detection

Fishes have an impressive complement of hydrodynamic and acoustic sensors, commonly referred to as the lateral-line and inner-ear sense organs. The basic receptor elements are the hair cells, which detect the minute displacements imparted to their apical ciliary bundles (Fig. 4.1a). The directional sensitivity of the individual receptor cells is indicated by the asymmetric position of the single kinocilium relative to the several rows of stereocilia. Morphologically, the hair cells of the various sensory clusters are strikingly uniform. Their diversity in function is determined mainly by the peripheral structures coupling the ciliary bundles to the physical world that the animals inhabit.