Flagellates and heliozoans in the Greenland Sea ice studied alive using light microscopy

Abstract

The occurrence of flagellates and heliozoans in the Greenland Sea was determined from freshly collected samples and crude cultures established during the expedition ARK XI/2 onboard RV “Polarstern” in autumn 1995. The live material was collected from the water column, new ice, and multi-year ice floes, and examined with light (interference and phase contrast) and epifluorescence microscopy. Photographic and video techniques were utilised for the documentation. The observed general morphology of the cells, swimming motions, feeding behaviour and modes of reproduction assisted in the identification of flagellates. A total of 57 photo- and heterotrophic flagellate taxa, representing cryptophytes, dinoflagellates, haptophytes, chrysophytes, Prasinophyceae, chlorophytes, euglenids, choanoflagellates, kinetoplastids, protists of unknown affinity (Protista incertae sedis), and heliozoans, were found. Diatoms were excluded from this study. Newly forming ice, ice floes and cultures established from the ice samples contained almost twice as many identified flagellate taxa as the water column. In addition to general information on the community structure of flagellates and heliozoans, the light microscopical methods used here provided information on the need for additional microscopy, establishment of cultures, and the suitability of the material for experimental work.