Effect of initial body orientation on escape probability in prey fish escaping from predators

Abstract

Since the escape response is crucial to survival and hence to the fitness of species, several studies have attempted to elucidate the kinematic and behavioral components of the response that affect evasion outcome. The prey’s body orientation relative to a predator at the onset of the escape response (initial orientation) could affect evasion outcome, because the turn angle and its duration before the initiation of escape locomotion would be smaller when the initial orientation is more away from the predator. We tested this hypothesis by recording the escape responses of juvenile red sea bream (Pagrus major) in response to the predatory scorpion fish (Sebastiscus marmoratus) using a high-speed video camera. Our results show that an increased initial orientation (i.e., more away from the predator) increases escape probability. Our results also indicate that an increase in the initial orientation decreases the turn angle and its duration. The flight initiation distance tends to be small when the initial orientation is away from the predator, suggesting that the prey might have a blind zone of sensory perception. These findings highlight the importance of incorporating initial orientation into both empirical and theoretical studies of the kinematics of predator-prey interactions.Summary statementOur predator-prey experiments reveal that the prey’s initial body orientation relative to a predator affects the prey’s turn angle and its duration, and consequently affects escape probability.

Escaping from multiple visual threats: Modulation of escape responses in Pacific staghorn sculpin (Leptocottus armatus)

“…Behavioral and neurobiological studies have shown that the Stage 1 turning angles are affected by stimulus direction (Domenici and Blake, 1993;Eaton and Emberley, 1991;Kimura and Kawabata, 2018). The escape response typically avoid predation when the prey evades in the direction opposite to that of the approaching predators (Walker et al, 2005).…”

“…Hence, Stage 1 turning angles tend to be wide when the stimulus approaches fronting the prey and narrow when the stimulus approaches behind the prey (Domenici and Blake, 1993;Eaton and Emberley, 1991;Kimura and Kawabata, 2018). The optimal escape trajectory was suggested to be between 90° and 180° depending on predator speed (Domenici, 2002;Weihs and Webb, 1984).…”

Functional effect of vaterite – the presence of an alternative crystalline structure in otoliths alters escape kinematics of the brown trout

“…An additional acrylic divider was positioned above the aquarium (touching the water) preventing the distortions in the recorded video images due to the propagation of surface waves. As the distance between the acoustic/motion source and fish position may affect kinematics (Kimura and Kawabata, 2018), fishes were only stimulated when located about 11±2 cm from the stimulus. In addition, a fish was considered for stimulus only if its body centre of mass was at least 0.75 body lengths away from any wall and the anterior part of its body was oriented at an angle of less than 5 deg to the tank edge.…”