Motor correlates of learning behaviour: feeding on novel prey by pumpkinseed sunfish (Lepomis gibbosus)

The functional basis of learning in prey capture was investigated in the pumpkinseed sunfish (Lepomis gibbosus). Feeding performance of sunfishes was assessed when the fish were first fed a novel, elusive prey (guppies) and compared with their performance after several weeks of experience with capturing guppies. During these feedings electromyographic recordings were made to document the pattern of activity in four jaw muscles at the strike. With experience, the L. gibbosus improved their ability to capture guppies, and several changes in the pattern of muscle activity were associated with this improved performance. Average duration and maximum amplitude of activity in all muscles increased between trials. Previous studies of muscle activity modulation in fishes indicate that these changes could improve feeding performance on an elusive prey. Thus, specific modifications of muscle activity appear to be one functional determinant of feeding success in fishes.