Patterns of Excitation of the Lateral Line of the Ruffe

Studies on the lateral lines of the sprat { Sprattus sprattus (L.); Clupeidae; Clupeiformes) have shown that the patterns of excitation of the neuromasts in the canals on the head changed dramatically with relatively small changes of position of the fish with respect to a source (Denton & Gray, 1983; Gray, 1984). It was concluded that, in the case of the sprat, this sensory system was capable of providing the information needed to maintain position in relation to other fish in a school; cf . the work of Partridge & Pitcher (1980) on saithe ( Pollachius virens ; Gadidae; Gadiformes). The structure of lateral lines varies greatly between fish of different species and even between different parts of the same fish. It seems likely that these differences have evolved to meet different behavioural needs. An attempt has been made to understand the mechanisms of lateral line excitation in general. This has led to the development of methods to calculate first approximations of likely excitation patterns from a knowledge of the morphology of particular systems (Denton & Gray, 1988).