Meeting Abstract
Ribbon worms (phylum Nemertea) are regularly collected during benthic faunal surveys of the Southern Ocean and are an important component of their community. However, despite their abundance, Antarctic nemertean ecology, distribution, and diversity remain poorly known. For example, there are approximately 31 recorded species, 95% of which were described prior to 1934. Of these, a third have been designated either nomen dubia or species inquirienda, and most have short questionable descriptions from poorly preserved material dating from the late 1800’s. Only three species have been described using modern taxonomic methods that includes both imaging and description of external features with an accompanying DNA barcode. To assess Antarctic nemertean biodiversity, and to engage undergraduate students in authentic research experiences, I have been teaching a research methods course using DNA barcoding of nemerteans collected by dredge from several agencies. We have generated DNA extractions for 375 samples, and from these samples amplified 276 COI and 337 16S sequences, which are used here in phylogenetic and DNA barcode analyses. So far, we have discovered 62 nemertean species, suggesting there is a substantially richer nemertean diversity in the Southern Ocean than is currently recorded. Unfortunately, voucher images and details of living external anatomy are lacking for these samples, so positive assignment to described species is challenging. We describe geographic locality data and found several species are circumpolar in their distribution, and we can connect several species to planktonic larva. These data also allow us to start testing biogeographic related hypotheses for specific neonemertean clades. Imaging, description of external anatomy of living samples using accepted character sets, and DNA barcoding is the most important next step for describing Antarctic nemertean biodiversity.
