Summary
The hypothesis that naive shoal members begin to feed more quickly on a food, novel in type, location and required foraging technique, when informed group members are present was tested with bluntnose minnows (Pimephales notatus) foraging in shoals of various sizes. Naive individuals in mixed shoals (one-third of the shoal members experienced with the new food and two-thirds naive) of 3 fish, decreased their foraging latency as compared to those in shoals of 3 naive fish when foraging on a novel food. In mixed shoals consisting of 6, 9 and 12 individuals, naive fish did not begin foraging more quickly than those in shoals of the same size consisting entirely of naive fish. In these larger shoal sizes, the naive fish remained together near the bottom instead of following the smaller number of informed fish to the surface where the novel food was located.
Methodology
Bluntnose minnows (53.4 ± 0.5 mm (x̅ ± S. D.) total length) were collected by seine from Lake Opinicon, Chaffey's Lock, Ontario, Canada. 600 fish were housed at 20-23°C in groups of 20-30 in glass aquaria 51x27x20 cm with standing water filtered by a corner filter. Lighting conditions were maintained at 12L:12D.