Meeting Abstract

P3.100  Sunday, Jan. 6  Evolution of the Reproductive System of Urodasys (Gastrotricha, Macrodasyida) ATHERTON, S.*; HOCHBERG, R.; University of Massachusetts Lowell; University of Massachusetts Lowell sarah_atherton@student.uml.edu

Gastrotrichs are microscopic, hermaphroditic invertebrates with complex reproductive systems. In particular, species of Macrodasyida possess an array of accessory reproductive organs that function in sperm transfer and receival, but homology among the various organs is undetermined. The genus Urodasys includes thirteen species that form three “groups” based on the anatomy of their reproductive organs and their reproductive strategies: one group includes four species with paired testes and ovaries but no accessory sexual organs; the second group includes eight species with a single testis, paired ovaries and paired accessory reproductive organs; and the last group includes just a single species that is hypothesized to be parthenogenetic based on the absence of any testes or male reproductive organs. In this study, we investigate the phylogeny of the genus Urodasys using partial 28S rDNA sequences to gain insight into the evolution of the three different reproductive strategies.