Meeting Abstract

76.2  Sunday, Jan. 6  The aquatic-terrestrial transition of freshwater turtles from a dynamical systems perspective MAZOUCHOVA, N*; WILSHIN, S; HSIEH, T; Temple University; Royal Veterinary College; Temple University nicole.mazouchova@temple.edu

A multitude of complex environments are found on our planet and are inhabited by a variety of animal species exhibiting diverse forms of adaptation. Animals that must locomote across the land-water interface range from mammals, to birds, to reptiles or fish. Studies have focused on movement on unfamiliar terrain but fewer analyze the locomotor requirements when transitioning from one environment to another, such as at the land-water interface. We are interested in a dynamical system analysis of locomotor abilities of freshwater turtles when transitioning from swimming to walking. Freshwater turtles frequently utilize freshwater streams and ponds to hunt for food and emerge onto the shores to bask in the sun. We hypothesize that transitions may be asymmetrical with gaits being specialized for escape and others for prey pursuit. The animals are kept in a freshwater tank outfitted with a dry-land dock and equipped with a high-speed video camera to film their behavior and kinematics during transitions between land and water. A simple dynamical systems model is fitted to the kinematics of the flipper motions during the aquatic/terrestrial transitions to explore patterns of gait changes between these two environments. The model captures the variability in the phase of the flippers and any phase locking of the transition onset. We will examine how the structure of the gait transitions affects performance of the turtles.