Meeting Abstract
The polychaete Polyeunoa laevis is a scale worm, often associated with gorgonians. This species shows a range of morphological variation; however, previous studies argued that two characters are useful for identification, shape of the neuropodial acicular lobe and most neurochaete being unidentate. Based on morphological studies, P. laevis is reported to be widely distributed in the southwest Atlantic, sub-Antarctic, and Antarctic regions. To asses if traditional morphological characters are useful in species identification, 93 individuals were sequenced for the mitochondrial marker COI. Sampling sites include Southeastern Argentina (SEA), West Antarctic Peninsula, Northeast Antarctic Peninsula, Weddell, Bellingshausen, Amundsen and Ross Seas. Preliminary molecular phylogenetic analyses recover 3 clades. One corresponds to the SEA region, a second clade includes most of the samples from east Antarctica and the Ross Sea, and the third clade includes most of the samples from west Antarctica. The two clades recovered from the southern ocean correspond to differences in the temperature of water masses. This study suggests some connectivity between the two clades found in the Southern Ocean, but genetic differentiation between the SEA and Southern Ocean. Open ocean barriers might be limiting the dispersal ability of this species and consequently impeding gene flow. Specimens from the SEA were also morphologically different suggesting a possible unrecognized species level diversity. More sampling sites with focus on the Argentinean waters and the East region of the Antarctic, combined with a more detailed morphological study, will help to elucidate the current taxonomic status and the genetic connectivity of these organisms.
