Meeting Abstract
Antarctic notothenioids offer a rare example of an adaptive radiation in marine vertebrates. During the dramatic cooling of the Southern Ocean over the past 40 million years, most near-shore fish lineages were locally extirpated. However, the evolution of anti-freeze glycoproteins in notothenioids enabled these ancestrally benthic fishes to survive in their frigid environment, and their evolution of secondary pelagicism fostered their diversification and occupation of newly available pelagic habitats. Antarctic notothenioids now represent the primary teleost lineage in the Southern Ocean and are of fundamental importance to the local ecology. However, little is known about how morphological innovations have contributed to their evolutionary success. In this study, we used a 3D-morphometrics approach to investigate patterns of morphological variation in the craniofacial skeleton, which is directly associated with prey capture and thus plays a key role during exploitation of novel ecological niches. In total we analyzed 30 notothenioid species across all major lineages within this clade. With this resource we address the following questions: 1) What are the primary axes of morphological variation associated with the notothenioid radiation and how do they compare to patterns seen in other teleost radiations; 2) Have different regions of the notothenioid skull evolved at different rates (i.e., do they exhibit patterns of evolutionary modularity?)? These data will provide deeper insights into how fundamental aspects of the notothenioid skull have both facilitated and constrained the adaptive morphological radiation of this important group.
