RUI: Evolution of Vertebrate Design: Functional Morphology of a Novel Feeding Mechanism in Osteoglossomorph and Salmonid Fishes Christopher P. J. Sanford Hofstra University
This research will investigate the origin and subsequent evolution of feeding behaviors in two ecologically and economically important groups of fishes. The origin of novel feeding behaviors allows organisms to exploit new resources and is critical to their success, particularly when facing changes in the availability of food in the environment. New behaviors and functions can be the result of novel anatomical structures, modifications of pre existing anatomical structures, or simply changes in the sequence of muscle activity that control movement. The relationship between these three factors in the origin of new behaviors remains largely unexplored, but is crucial if we are to understand what drives evolutionary success. Using an integrative approach, the aim of this research is to determine how changes in the pattern of muscle activity relate to the origin of new behaviors and functions that are linked to fitness. Quantitative analysis of a novel feeding behavior that has evolved independently in two different groups of fishes will establish if new patterns of muscle activity are a common feature in the origin of new behaviors. This project is significant because it will provide the first rigorously tested example of a repeated and predictable change in function that is the direct result of changes in muscle activity in these fishes. It will also demonstrate the central role of muscle activity in providing a platform for new functions to evolve. Three approaches will be used to quantify a novel chewing behavior in both salmonids and bony-tongue fishes. This novel chewing behavior centers around an impressive bite between large teeth on the bony tongue and an opposing set of teeth on the roof of the mouth that is used to shred and disable prey. Cranial muscle activity will be recorded in representatives of these two groups of fishes during feeding events, and along with video, will provide an accurate picture of the functional consequences of any changes in the pattern of muscle activity during chewing. Traditionally, one of the difficulties in tracking the movement of bony elements of the head is that many structures important in feeding cannot be viewed externally. Thus, a new technology, sonometric ultrasound, will be used to track the movements of those elements not observable using video analysis. This research will provide a robust test of the extent to which muscle activity patterns change in the origin of new functions, and the level of muscle activity variation necessary to elicit important functional changes that can be linked to feeding success. The broader impacts of this study are extensive because it will provide important information on chewing behavior and thus optimal food sources in economically important fishes. The research will also provide training for a postdoctoral researcher. As this research is being conducted at a primarily undergraduate institution it will foster cooperative training and learning among all educational levels, from undergraduates to advanced-level researchers. The modern techniques and equipment used in this project will have significant, positive educational impacts through incorporation into several areas of a new undergraduate curriculum. Furthermore, this research program will attract well qualified individuals from underrepresented groups.
