Midlines in motion Connecting Midline Curvature Dynamics to Heading Change and Center of Mass Deflection in Fishes


Meeting Abstract

103-3  Sunday, Jan. 6 14:00 – 14:15  Midlines in motion: Connecting Midline Curvature Dynamics to Heading Change and Center of Mass Deflection in Fishes HOWE, SP*; LEFFLER, D; ASTLEY, HC; Univ. of Akron; Univ. of Akron; Univ. of Akron sph43@zips.uakron.edu

Fish maneuverability is a complex and dynamic behavior. Most research on fish maneuverability has focused on stereotyped maneuvers such as the C-start escape response, but routine maneuvers have highly variable kinematic outcomes. Prior studies identify preparatory and propagating stages of the turn, but have not linked body deformations in the fish to outcomes of the turn like heading change and center of mass deflection. Using high-speed video and image analysis software, we provide a detailed description of the midline kinematics of the giant danio (Devario aequipinnatus ) and track the orientation of the fish as well as the center of mass over the course of a maneuver. In all turns, regardless of experimental treatment or heading change magnitude, we observed an anterior to posterior propagating pulse of curvature along the midline of the body. This behavior can be modeled as a transient pulse with quantifiable amplitude, width, and velocity. We focus primarily on the relationship between center of mass deflection and curvature pulse statistics to establish functional links between the behavior of the fish’s body and the direction changes of the fish. We found that total heading change is correlated with average curvature, and rate of heading change correlates with pulse velocity. Maximum linear acceleration is correlated with pulse velocity, and angular displacement of center of mass correlates with average body curvature. We have observed more complex maneuvers where fish link pulses in quick succession. It appears that the general form of the pulse is conserved across these maneuvers and combining pulses augments the final outcome of the turn. A pulse based model of fish turning seamlessly integrates with steady swimming while also providing a mechanism to produce complex maneuvers.

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