Takayuki YunokiAldo R. EcheverriaReinaldo B. CholimaGuido MirandaFederico Moreno2026-03-222026-03-22202510.15560/21.2.318https://doi.org/10.15560/21.2.318https://andeanlibrary.org/handle/123456789/76864We conducted ichthyological surveys in the Biata, Geneshuaya, Benicito, and Yata Rivers, as well as Dos Naciones Lagoon. We recorded 182 species, including new records for Bolivia, such as Jupiaba citrina Zanata & Ohara, 2009, Moenkhausia melogramma Eigenmann, 1908, Spinipterus cf. acsi Akama & Ferraris, 2011, Tatia cf. gyrina (Eigenmann & Allen, 1942), Cetopsidium orientale (Vari, Ferraris & Keith, 2003), Nemuroglanis cf. furcatus Ribeiro, Pedroza & Rapp Py‑Daniel, 2011, and Batrochoglanis melanurus Shibatta & Pavanelli, 2005. Most of these species, reported for the first time in Bolivia, were previously collected in black‑clear water streams located in the Upper Amazon and/or the lowlands around the Guiana Shield and Brazilian Shield, far from the study area. enActinopterygiiAmazon rainforestTributaryWetlandGeographyFisheryGeologyarticle