Composição e distribuição temporal do ictioplâncton no rio Piquiri, bacia do alto rio Paraguai

Abstract

The aim of this study was to evaluate the composition and temporal distribution of ichthyoplankton in the Piquiri River and its relationship with environmental variables to support fish fauna conservation actions. Ichthyoplankton samples were collected in two cycles: between November 2017 and March 2018 (first cycle) and between October 2018 and March 2019 (second cycle). Parameters such as temperature, pH, electrical conductivity, and rainfall were analyzed. The taxonomic composition analysis revealed 25 species, six of which were long-distance migrators. Piaractus mesopotamicus and Pseudoplatystoma spp. predominated, suggesting that the area is used as a spawning site for migratory species. The highest densities of eggs and larvae occurred in December (first cycle) and February (second cycle), associated with increased conductivity and pH and decreased temperature. These results contribute to understanding reproductive patterns and their dependence on physicochemical factors, as well as reinforce the need for conservation actions for fishery resources in the region, emphasizing the importance of habitat connectivity for maintaining aquatic biodiversity. Keywords: Eggs and larvae of fishes, Migratory species, Pantanal, reproduction, spawning áreas.