Tactics of Fish Behavior in the Water Flow during Starvation

Individual movement parameters for the zebrafish Danio rerio and the Prussian carp Carassius gibelio during starvation for 12 days have been determined in an experimental hydrodynamic installation circular tank. The fishes represent two tactics of behavioral responses on starvation. The tactics of unidirectional responses have been manifested in the movement of individuals in one direction relative to the water flow on days 2–5 of starvation. The tactics of multidirectional responses have been manifested on days 10–12 of starvation as movements in different directions relative to the water flow. The population advantages of such behavioral tactics of fish response to an unfavorable factor are considered.