On a collection of enchytraeids (Oligochaeta) from first order streams in São Paulo State, Brazil

Abstract

A collection of 21 ethanol-preserved specimens of enchytraeids collected in first order streams in São Paulo State, Brazil, was whole-mounted on slides and investigated under light microscope. Eight species taxa were distinguished, belonging to Achaeta, Guaranidrilus, and Marionina. Five species could be named, one of them tentatively: Achaeta neotropica Černosvitov, 1937, Achaeta singularis Schmelz, 2008, Guaranidrilus oiepe Righi, 1974, Marionina argentea (Michaelsen, 1889) s.l., Marionina cf. seminuda Xie & Rota, 2001. Three further unnamed species taxa of Guaranidrilus were distinguished; two of them may be new species. The presence of sexually mature specimens of A. singularis allowed an emendation of the original description which was based on juvenile specimens. The rod-shaped crystals in the coelom of A. singularis are similar to raphides in plants and sponges, and

Keywords

• Annelida
• Clitellata
• freshwater biodiversity
• South America
• raphides