Transmission electron microscope analysis of virus-like particles in the freshwater lakes of Signy Island, Antarctica

Water samples from a range of fresh-water Antarctic lakes on Signy Island (South Orkney Islands: 60 degrees 45'S, 45 degrees 38'W) were examined for the presence of virus-like particles (VLPs) during the 1998/1999 field season. It was discovered that VLPs were ubiquitous, morphologically diverse and abundant, with high concentrations ranging from 4.9 x 10(6) ml(-1) to 3.1 x 10(7) ml(-1). Likely hosts include bacteria, cyanobacteria and eukaryotic algae. In addition, an unusually large virus morphotype was observed with a head diameter 370 x 330 nm and a tail 1.3 mu m long.