A PRELIMINARY-STUDY OF NE GREENLAND SHALLOW MELTWATER PONDS WITH PARTICULAR EMPHASIS ON LORICATE AND SCALE-COVERED FORMS (CHOANOFLAGELLIDA,CHRYSOPHYCEAE SENSU-LATO, SYNUROPHYCEAE, HELIOZOEA), INCLUDING THE DESCRIPTIONS OF EPIPYXIS THAMNOIDES SP-NOV AND PSEUDOKEPHYRION POCULIFORME SP-NOV (CHRYSOPHYCEAE)

The biodiversity of five shallow freshwater and slightly brackish pond s (North East Greenland; 79-81 degrees N) has been studied with partic ular emphasis on taxonomical and ecological aspects of loricate and sc ale-covered forms, i.e. choanoflagellates, chrysophytes and heliozoans . The material was collected in July 1993 as part of the IAAP Northeas t Water (NEW) Polynya programme and represents the northernmost freshw ater and brackish localities analyzed using electronmicroscopical tech niques. Morphometric data and physical, chemical and biological parame ters (pH, temperature, salinity, nutrients, chlorophyll-alpha) are pro vided for all ponds sampled. The light- and electronmicroscopical exam ination of samples revealed 2 choanoflagellates, 14 chrysophytes and 7 heliozoan taxa. Seven species are recorded from Greenland for the fir st time and two species are considered new to science, viz. Epipyxis t hamnoides and Pseudokephyrion poculiforme. A crucial difference was ob served on the one hand between the single land pond (location 33) char acterized by high diversity and high biomass, and on the other the gla cier and the ice flee melt ponds characterized by low diversity and lo w biomass. Biogeographically the community sampled displays significan t similarities with localities previously investigated within the Gree nland and northern Canadian region.