Meeting Abstract

P3.153  Sunday, Jan. 6  Muscular Organization of a Scyphozoan Jellyfish: Aurelia aurita ZIMMERMAN, K.L.*; SATTERLIE, R.A. ; University of North Carolina at Wilmington; University of North Carolina at Wilmington klz2540@uncw.edu

The musculature of the Scyphozoan jellyfish Aurelia aurita was studied and observed, specifically within the subumbrella. Previous studies have concluded that the subumbrella of Aurelia aurita is comprised of a uniform sheet of circular, striated muscle. Recently, radial distortions have been found in the musculature, and these irregularities appear randomly throughout the sheet of circular muscle. A radial distortion is defined as a band of muscle fibers that run in apparently random directions, including a radial component. We provide observations on the distribution, size and orientation of the radial distortions. We also describe a region at the edge of the subumbrella that lacks circular muscle fibers. A developmental series from the ephyra to the adult medusa has been examined to determine how the radial distortions in the musculature of the subumbrella develop throughout growth and maturation of the jellyfish. The width of the marginal muscle-free band has also been measured throughout a developmental series. This work has implications for understanding the kinematics of swim contractions, particularly with reference to the rowing movements of the bell margin and the asymmetrical contractions seen during turning and righting behaviors.