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

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

SNOW ALGAE FROM SIGNY ISLAND .17 strongly curved filaments forming multiple waves or helical coils, 2. filament consisting of more cells, 3. being thinner, and 4. partly the process of reproduction. It appeared in masses in Sample A, probably causing green snow in the locality. Green snow caused in the Antarctica by Raphidonema species was first collected by E. RAKOVITZA, biologist (1889) of the "Expedition antarctique de la Belgica" led by de GERLACHE DE GOMERY in 1897-9, in the area of the Droit de Gerlach. The collection was worked up by DE WILDEMAN (1900, 1935), writing, among others, as follows (1935: 19): "filament non ramifiés, septés et recourbes faiblement de diverses manières". . ."nous avons observé dans les récoltes nos 146 et 159, des filaments formés de 4 cellul : droits. . . (Fig. 7. a, b, c) légèrement falciformis, spirales (Fig. 7. d, e, f ) ou parfois d'allure irreguliôre, contournés, tels un (Fig. 7. g) dont il ne nous pas toujours été possible d'étudier la structure interne, et qui par suite ne serait peut-être pas a rapporter au type du Prof. von Lagerheim" (P. 20. Fig. 7. d, e, f). Filaments spirales à 4 cellules, g. Filament pluricellulaire." It follows from WILDEMAN'S remark that he, too, saAv in the green snow sample strongly curved Raphidonema filaments consisting of many cells, and assumed that they are not identical with the species Raphidonema nivale LAGERH. During his cyriobiological and cryophysiological investigations in the Antarctica in 1966, G. E. FOGG (1967: 281) counted 4770 Raphidonema cells in 1 mm

3 snow surface of the green snow originating from the Moraine Valley of Signy Island. On Coronation Island, he found in the green snow of Meier Point 115 cell, in the yellow snow of Factory Cove, Signy Island, 364 cells, in the yellow snow of Moraine Valley, Signy Island, 289 cells, indeed, also in the red snow of Factory Cove, Signy Island, 320 cells, per 1 mm

3 each, in the snow surface. FOGG'S investigations demonstrate the enormous number of individuals of microorganisms causing the discoloration of the snow surfaces. As is to be seen, green snow caused by Raphidonema species is a characteristic natural phenomenon in the islands bordering the Antarctica. According to investigations conducted so far, diverse algal species cause green cryoseston discolorations in the various islands of the Antarctica (KOL, 1971). Summary According to studies made heretofore, the cryovegetation of the Antartica can be considered rich in the islands surrounding the continent. Professor G. E. FOGG, London, forwarded to me two valuable snow samples collected by R. B. HEYWOOD, Officer in Charge, on Signy Island. In Sample A, the algal species Raphidonema antarctica sp. n., predominated in enormous masses (Pl. I. Figs. 4-7, 10-13, Plate II. Figs. 1, 2). The various dividing and reproductive processes of this interesting algal species are discussed in detail. DE WILDEMAN (1935) wrote first of the green seston discoloration caused by Raphidonema nivale LAGERH., in the South Orkney Islands. G. E. FOGG (1967) conducted quantitative and biological investigations on the green, yellow, and red snows of Signy Island, in 1966. So far, literature recorded red, yellow, and green cryosestons from the Antarctica. The cryosestons of the various islands are caused by different algal species. The relegation of the Chlamydomonas species causing the red snow of the Antarctica is still dubious ; in my opinion, the characteristic plant of the red Antarctic snow is Chlamydomonas antarcticus WILLE. Chlorosphaera antarctica FRITSCH predominates in 80 per cent in Sample B (Pl. I. Figs. 1-2, 8, 42, Plate II. Fig. 1), being one of the characteristic plants of