Distance discrimination of weakly electric fish with a sweep of tail bending movements

Abstract

Weakly electric fish use active electrolocation to identify objects. They generate electric field by the electric organ discharge and perceive the distortion of electric image with existence of certain object. There have been many researches to comprehend the electrolocation mechanism of electric fishes. It is known that the ratio between the maximal slope of electric image and its maximal amplitude can discriminate object distances, regardless of object size and conductivity. In this paper, we suggest that the temporal pattern with tail bending is another cue to disciminate object distances. As a result, the electric field pattern for a specific electroreceptor shows consistency, regardless of object size and conductivity, when the distance is constant. Also, the lateral location of an object significantly changes the temporal pattern of electric image. © 2011 Springer-Verlag.