Threat-Sensitive Responses to Disturbance Cues in Juvenile Convict Cichlids and Rainbow Trout

Abstract

We conducted laboratory experiments (1) to confirm the existence of a non-injury released disturbance cue in juvenile convict cichlids and rainbow trout, and (2) to determine if cichlids and trout exhibit a graded threat-sensitive antipredator response to varying concentrations of disturbance cues. The results of our first experiment demonstrate that both cichlids and trout exhibit significant antipredator responses (reductions in time spent moving, foraging rate and area use) to the odour of conspecifics that had been exposed to a realistic predator model but not to the odour of undisturbed conspecifics. The results of our second experiment demonstrate that cichlids and trout exhibit reduced time spent moving and foraging rates proportional to the concentration of disturbance cue detected. Together, these results confirm the presence of disturbance cues in cichlids and trout and demonstrate that disturbance cues provide sufficient information to allow for graded threat-sensitive responses.