Ichthyofaunal inventory of a sand pit lake in the Municipality of Tremembé, state of São Paulo, southeastern Brazil

This study evaluated the composition of the ichthyofauna in an artificial lake formed by sand mining in the floodplain of the Paraíba do Sul River, municipality of Tremembé, state of São Paulo, southeastern Brazil. Although anthropogenic in origin, sand pit lakes may provide suitable conditions for the establishment of diverse fish communities, including native, non-native, and exotic species. Monthly sampling was conducted from May 2021 to September 2022 at five sites distributed around the lake, using fishing rods, trap nets, cast nets, and sieves. A total of 32 species were recorded, belonging to seven orders, 13 families, and 31 genera. Characiformes (31.3%), Cichliformes (28.1%), and Siluriformes (25.0%) were the most representative orders. The high proportion of non-native taxa highlights the ongoing transformation of the regional ichthyofauna and raises concerns regarding potential ecological impacts on native communities. These findings reinforce the importance of continuous monitoring of artificial lentic systems and the assessment of species introductions, contributing to conservation planning and sustainable management strategies within the Paraíba do Sul River Basin. Keywords: fish species richness, invasive species, Paraíba do Sul River Basin.