Meeting Abstract

72.4  Tuesday, Jan. 6  Cranial diversity in Anguilliform fishes: does morphological disparity lead to lower levels of modular integration? MEHTA, Rita/S*; ALFARO, Mike/E; WAINWRIGHT, Peter/C; Univ. of California, Davis; Univ. of California, Los Angeles; Univ. of California, Davis rsmehta@ucdavis.edu

Fish skulls are highly complex musculoskeletal systems that have been used as a model for numerous biomechanical studies. Historically, the teleost skull has been broken down into the following functional units or modules: the oral jaws, hyobranchial complex, and opercular series. These modules are functionally integrated to perform important survival behaviors such as capturing, transporting (swallowing) and processing prey, and respiration. Although it is sometimes suggested that functional integration constrains evolutionary diversification, there are relatively few systems where this relationship has been quantitatively examined. Here we examine the design of the cranial system of a diverse group of teleosts, Anguilliform fishes. We propose to study the evolution of correlated trait evolution across different modules comprising the visceral skeleton of Anguilliforms as a means for understanding the evolution of functional integration. Specifically, we investigate the relationship between disparity within modules and how this affects the strength of their trait associations. Our preliminary analyses suggest that increased disparity in the lower jaw module appears to be correlated with morphological disparity of the hyobranchial complex. The length of the oral jaws and the cross-sectional area of the hyoid apparatus, not only appear to be strongly and inversely correlated, but attributed to the evolution of suction as a prey capture strategy. These and other planned analyses will be ultimately used to test whether the evolutionary innovation of biting as a prey capture strategy has increased cranial diversity in anguilliform fishes.