Fish fauna of the Pelotas River, Upper Uruguay River, southern Brazil

Abstract

The fish fauna of the Pelotas River, in the Upper Uruguay ecoregion of southern Brazil was inventoried. Samplings were performed quarterly between August 2013 and May 2014 at 14 sites in the Pelotas River and its tributaries, using gill nets of different mesh sizes, sein nets, cast nets and electrofishing. In total, 7,745 specimens were recorded, comprising 46 species, belonging to 13 families and five orders. Approximately 80% of the species belonged to the orders Characiformes and Siluriformes, as well as the families Characidae and Loricariidae, which included a greater number of species. Of the total species, 24% were endemic to the Upper Uruguay River, four were identified only at the genus level and none was considered non-native. Approximately, half of the 98 species previously recorded for the Upper Uruguay basin were also detected in this study. The tributaries of the Pelotas River exhibited different faunas with five exclusive species. Thirty species were present in both the tributaries and the main channel. In addition, higher species richness, as well as the presence of larger-sized species were observed in the main channel. Many of the species not restricted to the Upper Uruguay River have already been reported as part of the Taquari-Antas River fauna. However, the local biodiversity of this region is under several threats, such as land use and installation of small hydroelectric plants. These results highlight the importance of the conservation of plateau/upland rivers, especially in the Upper Uruguay ecoregion, which shows a peculiar fish fauna and endemism.

PRIMER REGISTRO DE LA CORVINA DE AGUA DULCE Plagioscion ternetzi BOULENGER 1895 (EUPERCARIA: SCIAENIDAE) EN EL RÍO QUEGUAY Y LA CUENCA DEL RÍO URUGUAY

“…Plagioscion ternetzi has been cited for Uruguay in general species lists since 1976 (Carrera, 1976), but only two registers with its exact location have been published that confirm its presence in the inner Rio de la Plata Estuary and at the mouth of Uruguay River, Near the Paraná River delta (Serra, Duarte, Zarucki, Fabiano and Loureiro, 2012) River (Serra, 2014) and the Queguay River (Paullier, Bessonart, Brum and Loureiro, 2019), this species has not been observed in the Uruguay River basin to date. Similar observations apply for the middle and upper Uruguay River sections in Brazilian territory, where the species has not been reported (Delariva, Neves, Baumgartner and Baumgartner, 2019). Plagioscion ternetzi is also consistently absent from species lists for the Uruguay River basin in Argentina (López, Miquelarena and Ponte Gómez, 2005), Uruguay (Lits and Kroeber, 2014) and Brazil (Malabarba, 2021).…”

Ficha de Crenicichla igara

“…Estados Rio Grande do Sul, Santa Catarina Biomas Mata Atlântica Bacias Hidrográficas Sub-bacia Guaíba, Sub-bacia Litoral SP PR SC, Sub-bacia Uruguai Alto, Sub-bacia Uruguai Médio Distribuição Endêmica do Brasil: Sim Crenicichla igara é endêmica do Brasil e conhecida da bacia do alto rio Uruguai, nos estados de Santa Catarina e Rio Grande do Sul (Kullander, 2003;Delariva et al, 2019).…”