Meeting Abstract

100.8  Wednesday, Jan. 7  Variability of prey processing in teleost fishes with a comparison to amniotes GINTOF, C.M.*; KONOW, N.Z.; ROSS, C.F.; SANFORD, C.P.; Hofstra University cginto1@gmail.com

Sensorimotor control mechanisms governing prey-processing muscle activity in teleosts is understudied. Examining variability in underlying motor-patterns across a broad phylogenetic sample may improve our understanding of the evolution and complexity of vertebrate sensorimotor control. We examined two questions: is muscle-activity during prey-processing in fishes 1) behaviorally stereotypic or cyclic and 2) exhibiting a conserved level of variation? We recorded EMG from the adductor mandibulae (AM) in Amia, Esox, three osteoglossomorphs and four salmonids to quantify chewing duration and variation, which also was examined in raking, a novel behavior in the two latter groups. Distinct chewing occurred in behavioral trains among all taxa, a pattern that at least superficially resembles cyclic chewing in amniotes. Moreover, fish chewing cyclicity (variability in AM onset-onset duration) fell within the range seen in amniotes. Raking occurred more infrequently than chewing and rarely in trains. Stereotypy (variability in AM onset-offset duration) of chewing and raking was compared among basal and derived taxa and between basal (Amia and osteoglossomorphs) and derived lineages (Esox and salmonids). While chewing and raking stereotypy and chewing cyclicity were conserved among salmonids, variability existed in osteoglossomorphs. Our results support other evidence that prey-processing in basal teleosts may be neurally pre-programmed and rigorously controlled by central pattern generators. Work funded by NSF IOB#0444891, DBI#0420440.