Elektrische Organe und Elektrorezeption bei Fischen. Nervöse Grundlagen der akustischen Kommunikation bei Insekten

As far as is known today, only fish, in the entire animal kingdom, possess special organs which produce an electric field. For several dozens of years now, many scientists have been interested in the biological significance of th is electric field. Particularly important was Lissrnann's discovery of the fact that the socalIed "weakly" electric fish, the discharges of which are not sensitive to man and were therefore unknown until now, use the electric field to locate objects in their environment. Many questions arose which had their origins in this discovery. What are the biological basis for a sensory system which allows for such a particular perception? It will be shown by morphological and physiological experiments that the aforementioned elec tro-sensory system works by autostimulation of the fish and that the rhythm of the pacemaker of the biological generator (the electric organ) is influenced by distortions which occur in the electric field. The biological significance of the electric organ discharges as signal for communication between specimens wiU also be discussed. Résumé D'après nos connaissances actuelles, certains poissons possèdent seuls de tout Ie règne anima I des organes spéciaux qui créent un champ électrique rythmique dans Ie milieu aqueux environnant. Depuis plusieurs années, de nombreux biologistes s'attachent à rechercher la signification biologiquc de ce champ.