Population Structure of Nacella Concinna (Strebel, 1908) (Gastropoda Nacellidae) at Admiralty Bay, King George Island, Antarctica, in Austral Summer 2010/2011.

Abstract

Antarctic intertidal zones are extremely stressful environments, and the limpet Nacella concinna (Strebel, 1908), colonize those areas at Admiralty Bay, King George Island. is species has the potential to be a biomonitor, since it su ers the direct e ects of environmental variations and anthropic impacts. In the summer of 2010/2011, specimens of N. concinna were collected in three sites in Admiralty Bay, in order to investigate its population structure variability. Most individuals were larger than 20 mm, i.e, most of them were adults, with positive allometric growth. In general, sex ratio was 1.5 females to one male. Limpet population structure near the Brazilian station did not present any atypical values, but, temporal analyses are necessary for more precise evaluation. Spatial di erences found not only should be considered a response to natural physical factors such as wave action and food availability, but also to biological factors, such as seagull predation.