| The structure and behavioural response of the lateral line canal system of a nocturnal predator, Siniperca chuatsi collected from the Junjiang Fish Farm (Hanyang County, Hubei Province) in October, 1990. and in May, 1991 were studied by Jakubowski’s method for manifestation of lateral line canals and their neuromasts and observing the behavioural response of aquaria fish to mechanical stimuli.
This study of the canal system structure revealed a cutaneous fringe running on each side up to the snout tip and back to the tail of the fish. The supraorbital and infraorbital canals were well developed with maximum canal lumen. Most of the neuromasts in the two canals were obviously big, and protected only by bony bridges. The lumen of other canals narrowed gradually backwards and downwards, and were covered with bone over large spaces.
Behavioural experiments on blinded fish showed two kinds of responses to stimuli of low frequency vibration (<10Hz) from different regions near the fish. The stimuli elicited feeding responses when applied before and over the fish mouth at behavior occurrence frequency of 51% and 55%. The fish was less responsive to stimuli from other regions near its head, at behaviour occurrence frequency below 30%. Alarm could only be observed when the stimuli were around the fish trunk.
The presence of the rather well developed supre-and infra-orbital canals and the less well developed other canals indicates that the former may serve as a good substitute sensory organ for eyes to detect movable prey, and the latter to avoid striking obstacles during feeding of the fish in darkness. |
