Meeting Abstract

P2.64  Monday, Jan. 5  Assessing the function of larval zebrafish pectoral fins during slow swimming GREEN, MH*; AHN, D-g; HO, RK; HALE, ME; Univ. of Chicago mhgreen@uchicago.edu

The biomechanics and neural control of vertebrate limbs have been subjects of much recent interest. During low frequency (slow) swimming, 5 day old larval zebrafish execute alternating pectoral fin beats coupled with tail beats. Here we extend our previous description of the kinematics and dynamics of the slow swimming gait using computational techniques and flow visualization. We describe the phase relationship between pectoral fin oscillations and axial curvature, which better reflects the timing of motoneuron input to axial muscle. In addition, we describe the swimming performance of an fgf morpholino (finless) larval fish, which lack pectoral fins, using a suite of kinematic parameters including swimming frequency, tail beat amplitude, head yaw, midline curvature, forward velocity, swimming episode length, distance traveled, and the advance ratio, a measure of tail beat efficiency. Flow visualization indicates that the pectoral fins of wild type larval zebrafish move water from anterior to posterior during slow swimming and thus may be involved in producing thrust or stabilizing force. However we find similar advance ratios and axial swimming kinematics in finless and wild type fish. It is possible that the larval pectoral fins are important for aspects of kinematics that we have not yet assessed; alternatively, this fin-axis coordination may represent a coordination pattern that is important for function in slow swimming later in the larval stage or in a different behavioral context.