Meeting Abstract

P2.97  Sunday, Jan. 5 15:30  A comparative study of damselfish cranial development (Family Pomacentridae) WIRGAU, R.W.*; SWEET, E.; COOPER, W. J.; Washington State University; Washington State University; Washington State University rachel.wirgau@email.wsu.edu

The damselfishes represent an extremely successful lineage of near-shore reef fishes that have a high abundance on all coral reefs. The embryos of damselfishes with diverse skull shapes and feeding ecologies can be obtained from both captive rearing and from the wild, which presents a unique opportunity to examine how changes in skull development have produced different adult damselfish head shapes. Here we present a comparative examination of embryonic skull development (fertilization-hatchling) in 12 species of damselfishes that occupy a range of adult feeding niches. Our objective is to understand how early developmental patterning determines larval and adult jaw shape, and to determine how larval jaw shape is connected to adult jaw shape. We used in situ hybridization labeling of the gene dlx2a, which is expressed in the cranial neural crest cells that form the pharyngeal arches, in order to visualize the formation of the first pharyngeal arch (i.e., visualize initial jaw patterning). We combined this developmental work with morphometric analyses of larval jaw shape using hatchlings of the same species. It is at the hatchling stage that first feeding (first jaw use) occurs. We used a similar approach to examine skull form in adults. Our research examined the developmental factors that shape cranial divergence using a larger number of species than has been previously examined in this context.