The behavioral response of Notropis artherinoides to a simulated avian predatory attack and the effect of stimulus profile on school density.

Natural History & EvolutionThis study was conducted to determine how schooling characteristics of the emerald shiner, Notropis artherinoides, change in response to the introduction of an avian predatory stimulus. An additional objective was to determine if minnows differentiate between potential predatory threats based on predator profile. Three silhouettes representing a circle, a square, and a cross were flown over a school of 37 shiners. This was repeated three times with varying orders of presentation. Schooling was video-recorded and measured in terms of distance to nearest fish. It was observed that school density was lowest during the introduction of a stimulus, and that there was no significant difference in density between schools observed before and after a stimulus. Furthermore, it was found that distance to nearest fish did not vary with respect to stimulus profile. These findings suggest that emerald shiners do not distinguish potential avian predators based on profile and that passing shadows stimulate a cooperative defensive response.http://deepblue.lib.umich.edu/bitstream/2027.42/88642/1/Quinn_David_2011.pd