Meeting Abstract

94.1  Saturday, Jan. 7  Comparison of lower jaw levers in the oral jaws of early life history stage drums (Family Sciaenidae) of the Chesapeake Bay DEARY, Alison/L*; HILTON, Eric/J; College of William and Mary, Virginia Institute of Marine Science, Gloucester Point, VA; College of William and Mary, Virginia Institute of Marine Science, Gloucester Point, VA aldeary@vims.edu

In fishes, a correlation exists between the morphology of the feeding apparatus and the foraging ecology. Although numerous biomechanical models of the fish jaws and skulls have been tested, relatively few actinopterygian fishes have been examined to understand the morphological diversity and ontogenetic changes of lever mechanics. The goal of this study is to examine the lever mechanics of the lower jaw in the family Sciaenidae during ontogeny to determine if and when changes are observed and how they relate to foraging ecology. Sciaenids along the East Coast of the United States are able to partition their niches through variation in the oral jaw structure as adults. However, very little is known about the link between morphology and foraging ecology outside of the adults, especially in sciaenids. Jaw elements were measured using a Zeiss SteREO DiscoveryV20 microscope after specimens were cleared and stained and stomachs were removed. The stomach contents were analyzed using a compound light microscope and contents were classified into broad taxonomic groupings by the prey’s primary habitat (i.e. benthic crustacean, pelagic crustacean, etc.). Sciaenids have significantly different premaxilla, lower jaw, and ascending process lengths by 20.0 mm standard length (SL), suggesting that early life history stage sciaenids do exhibit differences in the oral jaws that reflect the foraging ecology of the adults. I hypothesize lever mechanics will also exhibit significant differences by 20.0 mm SL, further suggesting that sciaenids may be able to partition their niches before reaching the late juvenile stage.