Meeting Abstract
Fishes use many different combinations of fin and body kinematics to get around in aquatic environments. In order to study this variation in a functional context, we need methods of quantitatively describing and comparing these kinematic strategies. Approaches to quantifying steady swimming gaits have recently been developed. These approaches, while valuable, cannot be applied to the many, biologically important unsteady swimming behaviors that characterize fish movement, e.g. escapes from predators and linear accelerations towards prey. Based on the approaches established for steady swimming, we used several different (admittedly simplified) analytical schemes to try to quantify fish caudal fin acceleration kinematics in bass and trout. We examined three different observer-defined behaviors: steady swimming, linear acceleration, and burst acceleration, over a range of initial speeds, to assess how these approaches capture behavioral variation. The analyses, based on techniques used in digital signal processing, trigonometry, and regression modeling, are limited, but each provides information relating kinematics to acceleration performance. Given their limitations, the approaches presented are intended to invite discussion regarding which quantitative tools we have at our disposal to study unsteady swimming kinematics, and how we might apply them. These preliminary approaches underscore the complexity of fish kinematics, and the need for multi-fin, multi-variate methods.
