SPECIES OF THAUMATOMASTIX (THAUMATOMASTIGIDAE, PROTISTA-INCERTAE-SEDIS) FROM THE ARCTIC SEA-ICE BIOTA (NORTHEAST WATER POLYNYA, NE GREENLAND)

The sea ice biota of polar regions contains numerous heterotrophic fla gellates very few of which have been properly identified. The whole mo unt technique for transmission electron microscopy enables the identif ication of loricate and scaly forms. A survey of Arctic ice samples (N orth-East Water Polynya, NE Greenland) revealed the presence of ca. 12 taxa belonging to the phagotrophic genus Thaumatomastix (Protista inc ertae sedis). Species of Thaumatomastix possess siliceous body scales and one naked and one scale-covered flagellum. The presence in both Ar ctic samples and sea ice material previously examined from the Antarct ic indicates that this genus is most likely ubiquitous in polar sea ic e and may be an important component in sea ice biota microbial activit ies.