Kinematics and directionality of body turning in water striders (Gerris argentatus) on the water surface.

Abstract

Water striders inhabit the elastic surface tension film of water, sharing their environment with other aquatic organisms. Their survival relies heavily on swift maneuverability and navigation around floating obstacles, which aids in the exploration of their habitat and in escaping from potential threats. Their high agility is strongly based on the ability to execute precise turns, enabling effective directional control. This paper investigates the intricate coordination of leg movements essential for initiating and sustaining turning maneuvers in water striders. We elucidate the distinct roles of each leg in modulating posture and stability during turns, with a focus on the pivotal role of the midlegs in maintaining directional movement. Through analysis of leg accelerations, decelerations, and load distribution, we unveil the spatiotemporal dynamics governing successful turns. Our findings reveal refined turning strategies employed by water striders in varying situations, from narrow to wide turns, characterized by adaptations in their locomotor system, particularly in the widening of the sculling field. Additionally, we report the phenomenon of reverse sculling, a novel escape tactic of water striders. By shedding light on the maneuverability of water striders, this study contributes to a deeper understanding of animal locomotion strategies in aquatic environments.