SAMARCO, Thomas/ J.*; TURINGAN, Ralph/ G.; Florida Institute of Technology; Florida Institute of Technology: Intraspecific Variation in Scaling of Prey Capture Kinematics in the teleost fish, Sciaenops ocellatus
Body size influences the ability of an organism to function in its environment. Previous studies involving a wide range of body size of fishes revealed that feeding kinematics exhibit a constant scaling pattern through ontogeny. Here we present the first empirical analysis of variation in scaling coefficients of prey capture kinematics between larval and juvenile stages of a teleost fish. We recorded prey capture behavior using high speed videography in larval (2-8 mm SL) and juvenile (40-135 mm SL) red drum, Sciaenops ocellatus. Films were played back frame by frame to measure linear excursions (e.g., gape, hyoid depression, and premaxillary protrusion) from key feeding structures. Times to reach peak values of these kinematic variables were also recorded. All kinematic variables were log10 transformed and plotted against log10 transformed standard length of fish. Maximum gape, hyoid depression, premaxillary protrusion, and all timing variables showed major ontogenetic changes due to an increase in fish body size. Our analyses revealed two scaling patterns of prey capture kinematics; one for larval fish and one for juvenile conspecifics. Larval fish had shorter timing durations than expected based on the scaling patterns of juvenile fish. These results suggest that fishes undergo a major change in the nature of the relationship between prey capture kinematics and the physical environment from the larval to the juvenile stages of their life history.
