Zooplankton diversity in freshwater environments of Parintins, Amazonas, Brazil

Abstract

This study presents a taxonomic survey of the zooplankton community in Parintins, located on the right bank of the Amazon River, Amazonas State, Brazil. Sampling was carried out at ten sites encompassing lentic and lotic environments during the rainy (June–July 2022) and dry (October–November 2022) seasons. Zooplankton samples were collected through horizontal subsurface tows using a 64 μm plankton net and analyzed under light microscopy. A total of 118 taxa were identified, belonging to eight main groups: rotifera, protozoa, chromista, branchiopoda, copepoda, diptera, gastrotricha, and nematoda. Taxonomic richness was higher in lentic environments (99 taxa) and during the dry season (93 taxa). Rotifera and protozoa were the most representative groups, followed by chromista and branchiopoda. Seventy-nine taxa represent first records for the lower Amazonas region, highlighting the importance of taxonomic inventories in underexplored Amazonian areas and contributing to biodiversity knowledge and environmental monitoring in the context of urbanization and hydrological variability.