Meeting Abstract

S3-1.8  Jan. 4  “Evolution of holopelagic annelids” or “Going pelagic when your relatives are stuck in the mud” HALANYCH, K.M.*; STRUCK, T.H.; Auburn Univ.; University of Osnabr�ck ken@auburn.edu

Annelids are most commonly thought of as soil dwelling or benthic organisms. However, several annelid lineages have adopted a holopelagic existence. Some groups, such as tomopterids, are fairly well-known and familiar to students of marine plankton samples. Other groups, including typhloscolecidae and Poeobius, are less familiar as they occur in deep water or open oceans. One common feature of annelid lineages that have adapted a holopelagic existence is the considerably modified morphology compared to their benthic relatives. They often lose key morphological features such as segmentation or chaetae. This study examines the origins of various lineages of holopelagic annelid species using molecular phylogenetic data. An explicit attempt is made to understand how morphology is modified to allow for this change in habitat, and to look for common patterns across evolutionary lineages.