This study aimed to identify the species belonging to the genus Micrasterias from "Lago Municipal de Cascavel" and contributes to the knowledge of its taxonomic composition and geographic distribution in Paraná State. Taxonomic survey was based on monthly samples, performed from January 2002 to October 2003. Samples were collected using plankton net (25 µm mesh size) and immediately fixed in Transeau solution. Qualitative analysis and illustrations were conducted with the aid of an optical microscope with drawing tube. Nine taxa were recorded: Micrasterias borgei Krieger var. borgei, Micrasterias denticulata Brébisson ex Ralfs var. denticulata, Micrasterias jenneri Ralfs var. jenneri, Micrasterias laticeps Nordstedt var. laticeps, Micrasterias laticeps Nordstedt var. acuminata Krieger, Micrasterias quadridentata (Nordstedt) Grõnblad, Micrasterias rotata (Greville) Ralfs var. rotata, Micrasterias thomasiana Archer var. notata (Nordstedt) Grõnblad and Micrasterias truncata (Corda) Brébisson ex Ralfs var. truncata. Micrasterias jenneri var. jenneri and Micrasterias quadridentata are cited by first time in Paraná State.
Cascavel Municipal Lake; desmids; phytoplankton; taxonomy
