Ichthyofauna of sandy beaches along the Acre river, Brazil

Abstract

Despite increasing efforts in recent years to catalog the fish diversity of Amazonian rivers, many regions are still under-sampled, and sandy beach environments are particularly poorly understood. The present study focused on a 300 km stretch of the Acre river, in the southwestern Amazon basin, where we sampled 30 sandy beaches separated by a mean interval of 10 km. We collected 15,329 fish representing 80 species, 26 families, and nine orders. The Characiformes were the most abundant order, providing 88.24% of the individuals collected, followed by the Siluriformes, with 10.03%, while the Siluriformes had the highest species richness, with 37 species (45.0%), followed by the Characiformes, with 30 (37.5%). The most abundant species were the characiforms Knodus orteguasae and Creagruto barrigai. Reliable data on a region’s biota is fundamental for the evaluation of patterns of biodiversity, and the occurrence and management of threatened species. As fish are directly affected by pollutants and the degradation of aquatic environments, further research in areas that are still poorly sampled will be essential for the elaboration of effective conservation strategies.

Distribution extension of Curimatella immaculata (Fernández-Yépez, 1948) Curimatidae, Amazon, Brazil

“…New species are described each year, and the estimates exceed 9,000 species (Reis et al, 2016;Birindelli and Sidlauskas, 2018), for the Neotropical region. For the many water resources that form the Amazon basin, the Acre river is a mediumsized watercourse, by the standards of the Amazon basin, running 1190 km from its source, in Peru, to its confluence with the Purus river in the Brazilian state of Amazonas, first passing through Bolivia and then the state of Acre, Brazil (Silva et al, 2020). For the many water resources that form the Acre river basin, the hydrographic basin Quinoá stream (HBQS), a tributary of the right bank, is an important ecosystem that must be conserved for ecological maintenance and balance (Acre, 2012;Corrêa et al, 2018).…”