Can juvenile Atlantic salmon use multiple cue systems in spatial learning?

An ability to form a map or spatial representation of a home range should facilitate efficient foraging and promote the use of effective escape routes to shelter. Although a few experiments have shown some species of fish are capable of simple spatial behaviour, little is known about the behavioural mechanisms they use to orient as they forage. Whether juvenile Atlantic salmon, Salmo salar, have the capacity to use conspicuous visual landmarks to help them track a moving resource was investigated. The experiment was then modified to determine whether the salmon could continue to track the resource in the absence of conspicuous visual cues. The salmon followed a moveable food source in the presence and, after retraining, in the absence of distinct coloured landmarks. It is suggested that juvenile salmon may be capable of using multiple forms of cue to help them solve spatial tasks such as tracking a moving resource. (C) 1996 The Association for the Study of Animal Behaviour