Amebas testáceas (Protozoa, Rhizopoda) de ambientes límnicos do Parque Nacional da Lagoa do Peixe, RS, Brasil

Abstract

Quantitative and qualitative analyses developed with dead and living testate amoebae were carried out in Lagoa do Peixe National Park, near the central portion of the external coastal plain of the Rio Grande do Sul State, south of Brazil. Samples collected in bottom sediments from distinct lothic and lenthic environments show Difflugia oblonga, Pontigulasia compressa and Cucurbitella mespiliformis as the dominant species in the dead assemblages of the lenthic environments, the last two also present in the living assemblage. In the lothic dead assemblages the dominant species are Hoogenraadia africana, Centropyxis platystoma , D. oblonga and C. mespiliformis , the first three also dominating the living assemblage. Six species were exclusive from calm body waters and 10 to river streams, attesting more favorable conditions of life and/or preservation of these microorganims. A rare form of the freshwater foraminifer Plagiophrys sp . was observed for the first time. Key words: testate amoebae, Recent, Lagoa do Peixe National Park, Brazil.