Sound and Startle Responses in Herring Shoals

Abstract

The behavioural experiments described in this paper were carried out to complement earlier physiological work on the acoustico-lateralis system of the clupeid fishes. Previous work, summarized by Blaxter, Denton & Gray (1981a), has shown that the sense organs of the clupeid utriculus are highly sensitive to alternating pressures. Since the utriculus signals the polarity and amplitude of each peak in a complex pressure wave form separately, independently of the rate of change of pressure over a range equivalent to a frequency band of 30–800 Hz, it is well suited to give information on brief noises. In the clupeids the lateral line is hydrodynamically connected with the ear and we have suggested that the signals arising from the inner ear and the neuromasts of the lateral line are used in conjunction to provide information about direction and range.