Meeting Abstract
69.7 Jan. 7 Ontogeny of fin function during routine turning in zebrafish (Danio rerio) DANOS, N.*; LAUDER, G.V.; Harvard University; Harvard University ndanos@oeb.harvard.edu
The importance of fin function in fish maneuvering has been highlighted by several recent studies. We are interested in the ontogeny of these functions in a model organism, the zebrafish Danio rerio, during routine turns interpreted as part of its food searching pattern. Dorsal view high-speed videos of 22 fish performing routine turns were captured at 1000 fps and 1024×1024 megapixel resolution. Fish ranged in size from 0.38 to 2.0 cm in fork length (FL). The images were analyzed using Digital Particle Image Velocimetry (DPIV) software with the algorithm applied to the light image of the animal instead of laser-illuminated particles in the water. This allowed us to automatically track the movement of the zebrafish body and the pectoral and caudal fins at high spatial and temporal resolution without the necessity of manually digitizing individual points. From the resulting data the following kinematic variables were collected: maximum fin velocity during a turn both in m/s and relative to body velocity at the base of the fin, maximum body curvature, angular velocity of the head, maximum and final angle of the turn and turn duration. The slope of the log-transformed variables against log-FL was compared to the predictions from geometric models of isometry. The angular variables, angular velocity and turn angle always had negative slopes which never exceeded -1. The single time variable examined, turn duration, was independent of log-FL. Velocity variables did not follow a consistent trend; some showed a slight negative slope and some a slight positive slope (always <1) while others scaled with a slope not significantly different from 0. Agreements and discrepancies with the models are interpreted in light of morphological changes over ontogeny as well as relevant hydrodynamic transformation from a viscous to an inertial regime.
