Ictiodiversidade em tributários dos Rios Correntes, Piquiri e São Lourenço na Bacia Do Alto Paraguai, Mato Grosso

Abstract

Knowledge of the basic ecological parameters of ichthyofauna is essential for the proper management of fish populations. Thus, the study aimed to characterize the spatial distribution of fish assemblages in sub-basins surrounding the Pantanal by surveying the composition and spatial variation of the richness, abundance and diversity of fish in the sub-basins of the Correntes, Piquiri and São Lourenço, belonging to the Upper Paraguay River Basin. Seven sampling points located at the plateau interface with the Pantanal Norte plain in the states of Mato Grosso and Mato Grosso do Sul, Brazil were delimited. The collections took place from November 2017 to March 2018 in a standardized way using different fishing devices (waiting nets, longlines and hooks). In total, 329 fish individuals were captured, divided into four orders (Characiformes, Siluriformes, Cichliformes and Gymnotiformes), 14 families, composed of 43 species. There was a greater representation of Characiformes followed by Siluriformes. The species richest families were Anostomidae with seven species, Characinae, Loricariidae and Heptapteridae with five species each, followed by smaller contributions from the others. The Piquiri River had the highest wealth (25 spp.) And specific diversity (2.80), but the lowest abundance (77 ind.), While the Comprido River had the lowest wealth (10 spp.) But the highest abundance of individuals (116 ind). The lowest diversity and evenness occurred in the Anhumas river (0.8953 and 0.6458, respectively) and the most uniform distribution was recorded in the Correntes river (0.8787). An exotic species (Oreochromis niloticus - Tilápia) was registered in the inventory, one listed among the species almost threatened with extinction (Piaractus mesopotamicus) and a species not yet described in the genus Serrasalmus sp. Six species of commercial interest (target species) were registered in the Piquiri River, distributed in two orders and five families, with greater abundance of Schizodon borellii (Piau-três-pintas) Ichiodiversity was composed of common species in the neotropical region and there was wide spatial variation in the parameters analyzed in the community, whose occurrence of a new species record for the region and the appearance of exotic species reinforces the need for continuous surveys in the rivers that drain the plateau. adjacent to the North Pantanal.