Increased exposure to predators increases both exploration and activity level in Brachyrhaphis episcopi.

Two temperament traits, tendency to explore and activity level, were measured in a tropical poeciliid fish, the Panamanian bishop Brachyrhaphis episcopi. Open-field arena tests were used to quantify how predation pressure shapes activity levels and exploratory behaviours. Fish behaviour differed between high and low-predation populations. Fish that experienced higher levels of predation were both more explorative and more active. There were also some individual differences within populations; fish varied in their levels of exploration and activity in a novel open arena, but these differences were not related to sex or size. Together with previous studies on this species, these results indicate that there is a behavioural syndrome associated with predation pressure. Fish from high-predation populations are bolder, more explorative and more active than those from low-predation populations.