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 ponds (North East Greenland; 79-81 degree N) has been studied with particular emphasis on taxonomical and ecological aspects of loricate and scale-covered forms, i.e. choanoflagellates, chrysophytes and heliozoans. The material was collected in July 1993 as part of the IAAP Northeast Water (NEW) Polynya programme and represents the northernmost freshwater and brackish localities analyzed using electronmicroscopical techniques. Morphometric data and physical, chemical and biological parameters (pH, temperature, salinity, nutrients, chlorophyll-alpha) are provided for all ponds sampled. The light- and electronmicroscopical examination of samples revealed 2 choanoflagellates, 14 chrysophytes and 7 heliozoan taxa. Seven species are recorded from Greenland for the first time and two species are considered new to science, viz. Epipyxis thamnoides and Pseudokephyrion poculiforme. A crucial difference was observed on the one hand between the single land pond (location 33) characterized by high diversity and high biomass, and on the other the glacier and the ice floe melt ponds characterized by low diversity and low biomass. Biogeographically the community sampled displays significant similarities with localities previously investigated within the Greenland and northern Canadian region.