Comparative Morphology of the Reproductive System in Acoels (Acoela, Acoelomorpha) and its Implications for Taxonomy

The Acoela is a group of small, acoelomate worms, common in the meiofauna of the marine intertidal zone. As a systematic group, acoels represent a clear-cut and well defined unit-however, the status and interrelationships of many subgroups within the Acoela remain a matter of debate. The taxonomy of the group is chiefly based on characters of the reproductive system. Despite their apparent taxonomic significance, our understanding of such features as the male copulatory organs, spermatozoa, and bursal appendages is still quite limited. This dissertation is an attempt to broaden our knowledge of the reproductive organs in acoels by studying them in species whose taxonomic statu