Strombomonas Deflandre (Euglenophyceae) in aquatic environments in the Área de Proteção Ambiental de Ibirapuitã, Rio Grande do Sul State, Brazil

ABSTRACT This paper is the result of the taxonomic study of the genus Strombomonas Defl. in the Área de Proteção Ambiental do Ibirapuitã located in the southwest of Rio Grande do Sul State, Brazil. Samples were collected between March 2011 and March 2012 from ten sites, six in the Ibirapuitã River and four in lotic and lentic environments near the river. A qualitative analysis of 26 samples resulted in the identification of 18 specific and infraspecific taxa. A new combination is proposed: Strombomonas scabra (Playf.) S.M. Alves-da-Silva comb. nov. Strombomonas brasiliensis Conf. was registered for the first time in the State. Strombomonas verrucosa (Daday) Defl. var. verrucosa was the most frequent, occurring in a broad spectrum of environmental variables, such as electrical conductivity, pH, water temperature, silica and organic matter.