Levantamento da icitiofauna do Rio Comandaí (Noroeste - RS)

Abstract

Brazil is considered the country with the greatest ichthyofaunistic diversity, but the number of species in its aquatic ecosystems is still imprecise and difficult to estimate, with never-recorded hydrographic basins. The intensification of research on the freshwater fish fauna allows a better understanding of the dynamics of the species in order to think about local biodiversity conservation strategies. The objective of this work was to characterize the ichthyofauna existing in different parts of the Comandai- RS River, taking into consideration the seasons of the year. Four collections were carried out in three different points between February and October 2016, the first point in Guarani das Missões, the second in Salvador das Missões and the third in São Paulo das Missões. The method of collection was passive, through fishing nets. At the end of the collections, 303 specimens of 44 distinct species belonging to 13 families and four orders were counted. The season with the greatest abundance of species was spring with 25 distinct species, but in number of individuals the summer was the most abundant with 98. The point that obtained more number of individuals as well as of species diversity was in the city of Salvador das Missões, With 112 individuals. Among the species collected, it was observed that the species Loricariichthys anus was the most abundant, with 62 specimens, followed by the species Rhandia quelen with 42 individuals and Astianax fasciatus with 41 specimens. Of the 45 different species collected, 20 of them were obtained only one representative of the species. The highest biomass found was in Guarani. Abiotic data such as Water temperature Oxygen; Ph; Conductivity; transparency; Speed; Water level of each point were also evaluated.