“…Although the situation has been changing in the last two decades with an increase of studies (biological, ecological and systematic studies) in streams, there is a lack of knowledge in some regions such as in southern Brazil. Most studies in the state of Rio Grande do Sul refer to large rivers, lagoons or estuarine areas (Fialho et al 1998;Garcia and Vieira 2001;Bastos 2002;Garcia et al 2003;Majolo 2005;Maltchik et al 2005;Dufech and Fialho 2006;Garcia et al 2006;Petry and Schulz 2006;Ribeiro and Köhler 2007;Dufech and Fialho 2009;Flores-Lopes et al 2010;Saccol-Pereira and Fialho 2010). The only stream environment studies from Rio Grande do Sul are: Tagliani (1994), Becker (2002), Bozzeti and Schulz (2004), Vilella et al (2004), Hirschmann (2009), Silva (2009), Winkler-Sosinski et al (2009), Costa and Schulz (2010) and Volcan et al (2011).…”