| Benthic macroinvertebrate in four rivers, three in the Pelotas River basin (Divisa, Marco and Silveira rivers, in the headwaters of the Uruguai River) and one in the Taquari-Antas system (Antas River), a tributary in the Guaíba basin, in the state of Rio Grande do Sul, were identified. Two samples were collected in summer, autumn and spring, with one replicate in each river. The total of 28,961 specimens included members of Platyhelminthes, Annelida, Acarina, Insecta, Crustacea and Mollusca. The Silveira and Marco rivers showed significant differences in the indices of Shannon-Weaver (H), Simpsons Reciprocal (1/D), Margalef (DMg) and Equitability (E). The Silveira River showed the highest means of diversity and the EPT index (Ephemeroptera, Plecoptera,... |
