[Functional features of the electroreceptors of several electric and non-electric fish]

The effect of the electric, magnetic, and mechanical stimulation of the electroreceptors was studied in marine skates (Trigon pastinaca, Raja clavata, and Torpedo marmorata) by recording single nerve fiber responses. The following two types of backbround dischanges were found with regular activity and bursting. In some fibres the bursts of impulses appeared simultaneously with respiration while in the others the activity was suppressed. The current threshold of the clear-cut responses were equal to 10- minus 9--10- minus 11 A/mm-2. The activity of the electroredeptors was modified by introducing a conductive or nonconductive object into the water. High sensistivity of the electroreceptors to weak magnetic field was shown. The biological role of the electroreceptors is discussed.