Meeting Abstract

128.5  Tuesday, Jan. 7 14:30  Development in the invasive colonial ascidian Didemnum vexillum IRVINE, SQ*; STEPHENS, CE; Unv. of Rhode Island; Unv. of Rhode Island steven.irvine@uri.edu

D. vexillum is an encrusting invasive colonial tunicate. It shares a peculiar form of asexual development, called pyloric budding, with other didemnid ascidians. In pyloric budding two buds form on the esophagus. One bud forms a new thorax (siphons and branchial basket), while the other forms a new abdomen (digestive tract, heart and gonads). Curiously, the thoracic bud combines with the parent thorax to form a new zooid, while the thoracic bud combines with the parent abdomen. We have employed histochemistry and confocal microscopy to examine this asexual development in detail. The aim is to determine whether the particular form of budding in this species can help explain its prodigious invasiveness.