Ref ID : 2128
Wilhelm Foissner; Faunistics, taxonomy and Ecology of Moss and Soil Ciliates (Protozoa, Ciliophora) from Antarctica, with Description of New Species, Including Pleuroplitoides smithi gen. n., sp. n. Acta Protozoologica 35:95-123, 1996
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Fifty-nine moss and soil samples from the maritime and continental Antarctic were investigated for their ciliate fauna using the non-flooded Petri dish method. Collections were made from a variety of biotopes covering most principal soil and vegetation types of the region following a cline from 60-70 degrees S, i.e. of increasing climatic severity. Sixty-four species are found: 51 in region A (Signy Island and Livingstone Island), 16 in region B (Antarctic Peninsula), and 14 in region C (continental Antarctic, viz, Ross Island and South Victoria Land). Twenty-nine out of the 64 species were first records for the region, and 5 of them were new species. Mean species number per sample was markedly higher in region A (9.6) than in region B (1.0) and region C (0.9), reflecting a dramatic faunal pauperization with increasing climatic severity and, respectively, decreasing soil fertility. This is strengthened by the observation that all samples from region A contained ciliates, whereas they were lacking in half of the collections from regions B and C. This highly patchy distribution, as yet not found elsewhere, is very likely caused by the severe environment allowing few pioneers to establish permanent populations. As compared with temperate and tropical regions, the Antarctic ciliate species richness is decreased by at least one order of magnitude. The fauna is dominated by r-selected, bacteria and fungi feeding colpodids. The most frequent species were Colpoda ecaudata, C. steini, C. inflata, Pseudocyrtolophosis alpestris, Pseudoplatyophrya nana, and Cyclidium muscicola, clearly proving Smith's (1973) bi-polar biogeography of Colpoda to be a methodological artifact. Nine ciliate species are described or redescribed using standard methods: Pleuroplitoides smithi sp. n., Protospathidium serpens, Cyclidium glaucoma, Notohymena antarctica sp. n., Sterkiella thompsoni sp. n., Urosomoida granulifera sp. n., U. antarctica sp. n., Oxytricha lanceolata, and Paruroleptus notabilis. The genera Pleuroplites Foissner, 1988 and Pleuroplitoides gen. n. (dorsal brush isomorphic and composed of 2 rows with paired, shortened cilia) are united in the family Pleuroplitidae fam. n. (Acropisthiina with extracytostomal extrusome bundle on ventral side; dorsal brush composed of few isomorphic or many heteromorphic kineties).