Distribution of two species of the genus Nototanais spp. (Tanaidacea) in Winter Quarters Bay and waters adjoining McMurdo Station, McMurdo Sound, Antarctica

Abstract

Nototanais is the most commonly found peracarid crustacean genus in Antarctic waters. The only two species in the genus, Nototanais dimorphus and Nototanais antarcticus, have been found to have overlapping circumpolar distributions in depths from 7 m to 585 m around Antarctica. However, only one species, N. dimorphus, has been recorded during yearly sampling from 2000 to 2010 at nine shallow (12-36 m) benthic pollution monitoring sites in Winter Quarters Bay and waters adjoining McMurdo Station, McMurdo Sound, Antarctica. These stations varied by depth, anchor ice formation and anthropogenic contamination. In 2011 and 2012, 1071 specimens of Nototanais spp. were collected and separated by species, gender and life stage. N. antarcticus was confirmed to cooccur with N. dimorphus at four of nine long-term monitoring sites. One station had no occurrences of either species. N. antarcticus was found in very low abundances in relation to N. dimorphus, indicating that individual species distributions may be modified by pollution and anchor ice, among other biological factors.