Meeting Abstract

P1-103   -   #Scanallstars: Comparison of the Calcareous Endoskeletons of Sea Stars Using High Resolution 3D Imaging Turner, MS*; Donatelli, CM; University of Washington; University of Ottawa msturn@uw.edu

Sea stars, echinoderms of the class Asteroidea, are found in all ocean basins from the intertidal to the abyssal zone. Members of this class are radially symmetric as adults and contain an endoskeleton composed of small calcium carbonate spines called ossicles. This endoskeleton supports diverse morphologies among this group, with ossicle shape varying from interlocking spines to overlapping plates. Although the ossicle structure has been compared using 2D x-rays and scanning electron microscopy (SEM), little work has been done to compare their organization in three dimensional space. An understanding of the 3D structure of sea star ossicles is essential to understanding their function, as these structures are complex. The goal of this study is to explore the morphology of sea star skeletons and infer ecological characteristics such as habitat, distribution, diets and behavior. We took high resolution micro-CT scans of nine species of stars from multiple habitats in the San Juan Islands, Washington, USA. Using Slicer 3D, an open source software for image analysis and visualization, we isolated skeletal structures shared between species: ambulacral groove, ossicle plates, and any external features (ie. spines, pedicellaria). These isolated segments are ideal for comparisons across phylogenetic relationships and ecological traits.