Meeting Abstract

S1-2.1  Wednesday, Jan. 4  Mechanisms underlying the evolution of schooling behavior in sticklebacks GREENWOOD, A.K.*; WARK, A.R.; PEICHEL, C.L.; Fred Hutchinson Cancer Research Center akg@stanfordalumni.org

Schooling behavior is a strategy commonly used by fishes for predator avoidance. Like other social grouping behaviors, schooling has numerous benefits for participants, such as increased vigilance and predator confusion. However, schooling is also associated with costs, including increased competition for food and mates. As a result of these costs and benefits, schooling varies as a function of ecological context. We have identified variation in schooling behavior among two populations of threespine stickleback fish: an anadromous marine population and a freshwater benthic population. Marine fish school very strongly whereas benthic sticklebacks show a significantly reduced tendency to school. We developed an assay to rigorously measure the schooling behavior of individuals from these populations in the laboratory. This assay consists of a motorized “school” of artificial sticklebacks, and it elicits strong schooling behavior from marine fish. The model school assay can quantify two separable features of schooling behavior: the tendency to associate with the models as well as the maintenance of a parallel body position with the models. Marines spend substantially more time with the models than benthics and have a significantly more parallel body position. We are now using the model school assay to dissect the proximate genetic and neural mechanisms contributing to divergence in schooling behavior. We have used quantitative trait locus (QTL) analysis in benthic-marine F2 hybrids to identify the genetic basis for differences in schooling behavior. This approach has led us to identify both a candidate gene and a candidate neural substrate mediating the difference in body position when schooling found between marines and benthics.