THE IMPACT OF ODOR AND AMBIENT FLOW SPEED ON THE KINEMATICS OF THE CRAYFISH ANTENNULAR FLICK: IMPLICATIONS FOR SAMPLING TURBULENT ODOR PLUMES

摘要

Before organisms extract relevant information from olfactory cues, animals often actively sample the environment through sniffing, wing beating, or flicking of olfactory appendages. These processes serve to increase the local flow velocity and to facilitate the movement of chemical signals from the environment to receptor sites. Crustaceans flick their antennules to sample. While the kinematics of this process is beginning to be understood, modulation of antennular flicking in response to increases in ambient flow velocity or through stimulation from chemicals is unknown at this time. This manuscript details two studies that were performed to understand the kinematics on this behavior and their implications on sensory perception. In the first study, the kinematics of a flick from a restrained crayfish was analyzed in response to flow velocities of 1, 3, and 5 cm/s and in the presence and absence of odor at these three velocities. The second study sought to determine whether antennular flicking behavior changes as a function of crayfish's walking speed or in response to variations in odor source concentration. The first study clearly shows that flick kinematic parameters (flick acceleration, flick velocity, and flick angle deflection) are increased as the ambient flow is increased and are increased in response to chemical stimulation. The second study shows that bilateral antennular flicking is not performed during chemical orientation and that antennular flicking behavior does change as a function of walking speed of the crayfish or increases in source concentration.