Meeting Abstract

P1.131  Jan. 4  Evolutionary Relationships within Paracerceis, a Sphaeromatid Isopod Genus with Invasive Populations SAUNDERS, Katharine M*; SHUSTER, Stephen M; The University of Texas at Austin; Northern Arizona University k.saunders@mail.utexas.edu

The North American sphaeromatid genus, Paracerceis, includes 14 described species, whose evolutionary relationships are unknown. Paracerceis sculpta was first described from southern California, but also has populations in the Gulf of California, Mexico. The distribution of P. sculpta is now cosmopolitan, evidently due to its association with fouling communities and its ability to invade novel habitats. To examine evolutionary relationships within the genus, we used a 400 base pair sequence from the mitochondrial 16S ribosomal RNA gene. Our analysis included sequences from 3 Paracerceis species, as well as from 4 other species belonging to 2 currently recognized sphaeromatid subfamilies, Dynameninae and Sphaeromatinae. We compared the sequences obtained using maximum parsimony. This approach showed Paracerceis to be a monophyletic group within the Dynameninae, with Paradella more distantly related to Paracerceis than was previously thought. Understanding the evolutionary relationships among Paracerceis will provide information for future studies of invasive isopod populations as well as of the appearance and persistence of alternative mating strategies within this genus.