Meeting Abstract

18.2  Jan. 5  Congruent patterns of muscle activity and kinematics in modulation of a novel feeding mechanism in fishes KONOW, N*; SANFORD, CPJ; Hofstra University; Hofstra University nicolai.konow@hofstra.edu

Concurrent analyses of motor activity patterns and kinematics in a functional system, although rarely tested, can convey a detailed understanding of how changes in muscle activity can directly influence functional differences. We investigated the role of each of these components of function in facilitating modulation of a novel prey processing behavior (raking) found in two phylogenetically distinct teleost lineages. We fed an elusive, tenacious prey (goldfish) and a non-elusive, mallable prey (earthworm) to brook trout, Salvelinus and clown knifefish, Chitala. For each taxon, kinematic and muscle activity data were treated separately to establish whether congruent patterns exist between these components when feeding on different prey. Raking in Salvelinus was primarily driven by neurocranial elevation but is not modulated. In Chitala, however, raking is characterized by extensive pectoral girdle retraction which significantly increases during raking on elusive goldfish. This tendency was directly reflected in muscle activity patterns with prey-type differences in Chitala primarily being driven by duration variability in two of the three serially organized ventral muscles bracing the tongue-bite apparatus and connecting it with the pectoral girdle. We discuss these results in the context of a potential decoupling of function in this ventral subsystem of the tongue-bite apparatus. Supported by NSF IOB 0444891 and DBI 0420440.