LORICATE CHOANOFLAGELLATES FROM ELLIS FJORD, ANTARCTICA INCLUDING THE DESCRIPTION OF ACANTHOCORBIS TINTINNABULUM SP. NOV. (Ninth Symposium on Polar Biology)

Abstract

The ice-free Vestfold Hills is deeply dissected by fjords and has a number of lakes and lagoons with seasonal connection to the sea. These diverse aquatic habitats vary greatly in salinity, ice cover, temperature, water depth and water column mixing. As part of ongoing studies on these water bodies, we have sampled the plankton from a basin at the head of Ellis Fjord, some 10 km from the open sea, where the temperature was 2.6℃ and the salinity was between 37.6 and 38.4‰. In enriched cultures from a 25 l sample taken from this basin we have found the loricate choanoflagellates, Acanthoeca brevipoda, Acanthocorbis unguiculata, Diaphanoeca grandis, Stephanoeca complexa, S. norrisii and S. diplocostata. From this site we describe the new species Acanthocorbis tintinnabulum. The 25 l sample was integrated over 0.8 m which encompassed the boundary layer between oxic and anoxic waters. The sample was stored at ca. 4℃ for 3 weeks and was anaerobic for that period. The species enriched from the sample were therefore able to withstand prolonged anoxia