Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 64. (Budapest 1972)

Kol, E.: Snow algae from Signy Island (South Orkney Islands, Antarctica)

Microorganisms írom the snow of Signy Island By the kind mediation of Professor G. E. FOGG. London, I received two most valuable snow samples from the Antarctica: "Signy Island, South Orkney Islands, altitude 60°43

/ S., longitude 45°38' W. Antarctica, Natural Environment Research Council, British Antarctic Survey, Roland B. Heywood. Officer in Charge. Limnology". It is my agreeable duty to express my thanks, both to Professor G. E. FOGG and R. B. HEYWOOD. Officer in Charge, for the two valuable snow samples. Every cryological collection, originating from the Antarctica, is highly valuable for science. Collections deriving from such hardly accessible territories are priceless, and I am most grateful to all who make it possible to obtain snow samples and cryobiologieal materials deriving from these regions. The two snow samples from the Signy Islands contain two vastly different microorganism communities. I have designated the two samples as Sample A and Sample B. In Sample A, I found masses of Raphidonema antarctica sp. n. (PI. 1. Figs. 4-7, 10-30, photographs 2, 3). In Sample B, Chlorosphaera antarctica FRITSCH predominates (80%), accompanied by the following species: Chlamydomonas antarcticus WILLE (Pl. I. Figs. 32-39) in 10%, Mesotaenium berggrenii (WITTR.) LAGERH. (Pl. I. Figs. 40, 41) in 5%, and Cylindrocystis brébissonii MENEGH. fo. cryophila KOL, Cryodactylon aniartica KOL (Pl. I. Fig. 31), Scotiella nivalis (SCHUTTX.EW.) FRITSCH, Pleiirococcus vulgaris var. cohaerens WITTR., in 5%. Algae Chlorophyta Chlorosphaera antarctica FRITSCH (Pl. I. Figs. 1-3, 8-9, 42. Plate II. Fig. 1) Sphaerical cells, single or in small groups. Cellular diameter 10-30 p, usually with thick, occasionally with laminate cell wall (Pl. I. Figs. 1-3, 8). Cells mostly surrounded by a wide sphaerical sheath of transparent mucigale (Pl. I. Figs. 0, 42). Chloroplast sphaerical, no pyrenoid observed. Cells occasionally containing some starch. Fat drops along cell wall present, fat situated in many cases in a continuous ring (Pl. I. Figs. 1, 8). Diameter of cell surrounded by mucilage sheath 45-50 ju (Pl. I. Figs. 9, 42). Chlorosphaera antarctica was the most abundant in Sample B, occurring in cells of diverse developmental stages, from very young sphaerical cells attaining only some microns in diamaters to large (50 p in diam.) and dividing cells surrounded by a thick sheath of mucilage. Reproduction by cell-division. The microorganism was first described by F. E. FRITSCH (1912: 103-4) from the yellow snow of the South Orkneys. Chlorosphaera antarctica is one of the characteristicplants of the snow on these islands. It was not yet found anywhere else in the Antarctica. However, I found it in Alaska, (KOL, 1941), on firn snow surfaces and glaciers. G. E. FOGG (1907) recorded it from the yellow snow of the Signy Island and from the green .snow of Coronation Island.