Mechanophysiological Properties of the Supraorbital Lateral Line Canal in Ruffe (Acerina cernua L.)

In vivo measurements of the motion of the skin covering the supraorbital lateral line canal of the ruffe are presented. Stimulation of the lateral line with local oscillatory water motion evokes displacement of the skin which exhibits a characteristic node-antinode pattern along the length of the canal. Frequency responses of the skin show tuning with resonance frequencies comparable with the `best frequencies' of the cupula, suggesting that cupular dynamics is involved in the generation of the node-antinode pattern. Indeed, the experiments show that the node-antinode pattern is caused by the presence of the cupulae in the canal. A hydrodynamic model describing the dynamics of the skin is presented. The model accounts for many of the observed phenomena, and leads to the conclusion that the motion of the skin reflects the micromechanical properties of the sensory bundles of the hair cells underlying the cupula.