Meeting Abstract
91.4 Monday, Jan. 6 14:15 Modulating growth trajectories of the feeding mechanism in sympatric species may contribute to functional morphological diversity in teleost fishes TURINGAN, R.G.*; KENYON, J.E.; SHENKER, J.M.; Florida Institute of Technology, Melbourne; Florida Institute of Technology, Melbourne; Florida Institute of Technology, Melbourne turingan@fit.edu
The quest into the advancement of our understanding of organismal diversity has inspired our renewed interest in investigating the developmental and molecular bases of functional morphological diversity. In this study, we attempt to contribute to our understanding of the origins of functional morphological diversity by comparing the trajectories of growth in key components of the suction-feeding mechanism in teleost fishes through ontogeny. Growth trajectories were generated in larval, juvenile and adult fish ranging in size from 3.0 to 210.0 mm. We derived the scaling coefficients (growth rate) of the Suction Index (SI), as well as key components of SI including the physiological cross-sectional area of the epaxialis muscle and the mechanical advantage of the neurocranial rotation mechanism. We compared the stage-specific growth rate of these performance metrics between the suction-feeding bluegill, Lepomis macrochirus, and the durophagous redear, Lepomis microlophus. In all fishes, SI and its morphological determinants scaled positively with body size. At the larval through the juvenile stages, growth rates of these metrics were statistically similar in both species. However, in bluegill, SI growth rate in late juvenile- to adult-stage was at least seven times faster than that of the larval- to early juvenile-stage. SI growth rate remained the same in both larval and adult stages of development in redear. SI growth rate in the late juvenile- to adult-stage was about three times faster in bluegill than in redear. Results suggest that the divergence in growth rate of functional morphological traits contributes to the formation of organismal diversity.
