Changes in the predator-avoidance behaviour of juvenile guppies (Poecilia reticulata) exposed to pentachlorophenol

Abstract

The effects of pentachlorophenol on the predator-avoidance behaviour of the guppy (Poecilia reticulate) in response to largemouth bass (Micropterus salmoides) predation was investigated. There were no consistent effects of pentachlorophenol on habitat use or general behaviour of the guppies. In the presence of predators, all guppies occurred significantly more often alone, motionless, and in the top third of the water column in the nonopen areas. Nine variables associated with predator efficiency were monitored to determine which treatment groups of guppies were easiest to capture. The bass had significantly lower capture success, performed more strikes and chases, and spent more time chasing guppies from the untreated and 100 μg/L groups than those from the 500 and 700 μg/L groups. This suggests that the guppies from the two high treatment groups had a slower response to predator attack and could not maintain a prolonged escape burst of speed.