TAXONOMIC CHARACTERIZATION OF PSEUDOHAPLOCAULUS-INFRAVACUOLATUS NOV SPEC AND VORTICELLA-CHLORELLATA STILLER 1940, EPIPLANKTONIC PERITRICHS (CILIOPHORA, PERITRICHIA) ATTACHED TO COENOBIA OF ANABAENA (CYANOPHYTA), INCLUDING A REDESCRIPTION OF VORTICELLA-CHLOROSTIGMA (EHRENBERG, 1831)

Pseudohaplocaulus infravacuolatus nov. spec. and Vorticella chlorellat a STILLER, 1940, two peritrich ciliates attached to planktonic coenobi a of Anabaena sp. (Cyanophyta), were investigated using live observati on, silver impregnation, and scanning electron microscopy. Pseudohaplo caulus infravacuolatus differs from its nearest relative, P. anabaenae (STILLER, 1940), mainly by the location of the anterior contractile v acuole. Vorticella chlorellata has symbiotic green algae, a J-shaped m acronucleus, and a single, ventral contractile vacuole. The number of silverlines is very close to that of V. picta, but distinctly differen t from that of V. chlorostigma (EHRENBERG, 1931), an other green Vorti cella, redescribed for the first time, Vorticella rhabdostyloides KELL ICOTT, 1885 is recognized as a distinct species, but transferred to Ha plocaulus: H. rhabdostyloides (KELLICOTT, 1885) nov. comb. Likewise, V orticella fasciculata MULLER, 1773 is considered a distinct species an d transferred to Pseudovorticella: P. fasciculata (MOLLER, 1773) nov, comb.