ESCAPE TRAJECTORIES IN ANGELFISH (PTEROPHYLLUM-EIMEKEI)

Angelfish (Pterophyllum eimekei) escape in non-random trajectories when the stimulus is presented laterally, within an angular zone of approximately 30-120-degrees (discriminating zone). The circular plot of escape trajectories shows a bimodal pattern that cannot be revealed by linear analysis. Angelfish escape preferentially at 180-degrees and 130-degrees away from the stimulus, maximizing the distance covered from the stimulus and escaping at the limit of their discriminating zone, respectively. Angelfish correct their responses when turning towards the stimulus, suggesting that escape trajectories are modulated by sensory feedback.