Exceptional concentration of fish diversity in Yasuní National Park, Ecuador (Napo River Basin)
Eastern Ecuador’s lowland Amazonia is renowned for extraordinary biodiversity, yet many areas remain under‑sampled. This updated ichthyofaunal inventory for Yasuní National Park synthesizes literature and museum records to document 458 freshwater fish species across 47 families and 13 orders—surpassing all previous estimates. These species represent a major share of the Napo and Amazon Basin fauna. The absence of invasive species, combined with the ecological services provided by this rich assemblage, underscores the global importance of protecting and managing western Amazonian waters and lands.
Subject Tags
- Rivers
- Biodiversity
- Wildlife
Abstract
Background
Despite limited access and rather deficient sampling in many lowland areas of eastern Ecuador, scientists have been able to demonstrate that this specific region of Amazonia houses extraordinarily high concentrations of species within several taxa—terrestrial and aquatic, plant and animal, vertebrate and invertebrate.
New Information
In this work, we developed an updated list of the ichthyofauna of the Yasuní National Park (YNP), based on an extensive literature review and databases of the most representative ichthyological collections from Ecuador. Our results yielded 458 species of freshwater fishes distributed in 47 families and 13 orders. This number exceeded previous fish lists from YNP and accounts for a considerable proportion of species inhabiting the Napo River Basin as well as the entire Amazon River Basin.
The higher-than-previously-reported species diversity within this protected area, the services these species provide to humans and the absence of invasive species underscore the need for greater efforts and investment in protecting and managing western Amazonian lands and waters.
Citation
Escobar-Camacho, D., Valdiviezo-Rivera, J., Carrillo-Moreno, C., Argüello, P., & Swing, K. (2025). Exceptional concentration of fish diversity in Yasuní National Park, Ecuador (Napo River Basin). Biodiversity Data Journal, 13, e136476. https://doi.org/10.3897/BDJ.13.e136476
TNC Authors
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Carolina Carrillo-Moreno
Freshwater Conservation Specialist, Ecuador
The Nature Conservancy
Email: c.carrillo@tnc.org