Electrolocation based on tail-bending movements in weakly electric fish.

Weakly electric fish generate an electric field with their electric organ to navigate in space, detect objects and communicate with conspecifics. Several studies have examined how electric fish identify objects with their electroreceptors and use electric images for electrolocation. It has been argued that sensor readings from electroreceptors along the rostrocaudal line allow fish to determine the location of a target object. It is well known that the ratio between the maximal slope and the maximal amplitude of the electric image can allow the discrimination of object distances, regardless of object size and conductivity. In order to understand the temporal pattern of electric images, we used a model of electric field perturbation. Using the model, we suggest that the temporal pattern generated at an electrosensor during tail bending is another cue that can be used by the fish to discriminate object distances. The time course of electric sensor signals from a specific electroreceptor when tail-bending movements are applied can provide information about the lateral distance of a target object.