Meeting Abstract
Schooling is a prevalent collective behavior exhibited by about 80% of all known fish species during at least some phases of their life. School formations are characterized by strong polarization, and fish maintain reasonably discrete relative positions within the group. Such behavior has been associated with a series of advantages ranging from enhanced capacity to reproduce to increased survival rates during predator attacks. A precise school pattern, where fish are evenly distributed in a phalanx or diamond configuration, is also thought to increase locomotor efficiency when compared to solitary fish, because individual fish may take advantage of the vortices shed by their neighbors during swimming. Here we present data on schooling behavior of a forage fish, the inland silverside (Menidia beryllina). We analyzed tridimensional schooling patterns and dynamics in fish swimming in a flow tank at different speeds, during and following disruptions caused by feeding events, and present preliminary results on the effect of climate-related stressors on school formation. Fish school volume is reduced and flattened as speed increases, and individual fish switch position at a higher frequency when they are forced to increase speed. Introduction of food induces the fish to quickly and temporarily leave the school formation to feed, and the precision of fish returning to their position within the school is also quantified. Comparison of data from different flow and feeding conditions suggests that schools are rarely static as individual fish do not maintain the same position within the school for an extended period, and the general shape of the formation morphs as the interactions between individual shift over time.
