Fig. 2.

Social manipulations used to characterize differences in behavior and physiology as a function of aggression. Animals were moved to test tanks where we recorded the first 15-min of behavior at three time-points (Day 1, Day 2, Day 16). In the first observation period (Day 1) two males were moved to a test tank containing three females. We were agnostic as to which male would become dominant and scored behavior of both males. Twenty-four hours later (Day 2), we scored the behavior of the dominant and subordinate male in each tank. On Day 16 we introduced a novel intruder. To classify dominant males as stable or escalating aggressive, we counted the number of fish damaged in the interval between Day 2 and Day 16.