Meeting Abstract

P3.53  Saturday, Jan. 5  Hydrodynamic stability of the Painted turtle (Chrysemys picta) BENNETT, N.L.*; RIVERA, G.; BLOB, R.W.; Clemson Univ; Clemson Univ; Clemson Univ nlbenne@clemson.edu

Hydrodynamic stability in swimming animals can be defined as the ability to resist recoil movements of the body and maintain a given trajectory. Morphological features, such as rigidity, have been suggested to affect lateral recoil motions, such as yaw (rotational) and sideslip (translational). We evaluated longitudinal stability in a species of freshwater turtle, the painted turtle (Chrysemys picta) by measuring yaw and sideslip during rectilinear swimming. High-speed ventral-view videos were digitized to calculate recoil parameters and limb kinematics. Yaw was measured as (1) the maximum angular deviation between the midline and the swimming path, and (2) maximum angular deviation of the midline between left and right excursions for one limb cycle. Similarly, sideslip was measured as (1) the maximum linear distance between the turtle�s center tangent to the swimming path, and (2) the sum of the largest such distances during consecutive left and right movements. Motions of each limb were defined by the angle formed between the proximal segment of the fore- and hindlimbs (i.e., humerus and femur) and the body midline. We explain the relationship between recoil motions and limb kinematics through one complete limb cycle.