Meeting Abstract

60.1  Jan. 7  Sensitivity of utricular afferent fibers to intraspecific calling via inductive neural telemetry in free ranging oyster toadfish, Opsanus tau. MENSINGER, Allen F.; University of Minnesota Duluth amensing@d.umn.edu

Male toadfish acoustically attract females to nesting sites by producing �boat-whistle� calls. To determine how the fish localize sound underwater, inductive neural telemetry was used to record from microwire electrodes chronically implanted into the utricular nerve of the toadfish, Opsanus tau. The telemetry tag allowed both laboratory and field monitoring of unrestrained, naturally behaving fish. The sensitivity of utricular afferent nerve fibers to male toadfish boat whistle calls and pure tone stimulus was determined in water depths ranging from 0.4 to 1.0 meters. Hydrophones were placed approximately 5 cm above the otoliths to determine the physical characteristics of the sound impinging on the utricle. Approximately half the afferents fiber exhibited increased firing to sound stimulus with many showing directional sensitivity. Thus, toadfish may be able to use information from the utricular afferents to localize sound underwater.