Ichthyofauna in the last free-flowing river of the Lower Iguaçu basin: the importance of tributaries for conservation of endemic species

A rich and diverse ichthyofauna, including numerous endemic species, thrives in the last free-flowing stretch of the Lower Iguaçu River and its tributaries upstream of the Iguaçu Falls. The study, conducted between 2010 and 2016, recorded 76 fish species across 87,702 specimens, with Characiformes and Siluriformes being the dominant orders. Notably, 42% of the species were endemic, including rare or endangered species like Steindachneridion melanodermatum and Gymnogeophagus taroba. The research also identified key indicator species for different habitats, such as Ancistrus mullerae and Rhamdia branneri in tributaries within Iguaçu National Park (INP), highlighting the park's critical role in conserving endemic fish fauna. These findings underscore the ecological significance of undammed river stretches and tributaries, providing crucial insights to mitigate potential impacts from planned hydroelectric developments like the Baixo Iguaçu Hydroelectric Power Plant.

Pini, S. F. R., Makrakis, M. C., Neves, M. P., Makrakis, S., Shibatta, O. A., & Kashiwaqui, E. A. L. (2021). Ichthyofauna in the last free-flowing river of the Lower Iguaçu basin: the importance of tributaries for conservation of endemic species. ZooKeys, 1041, 183–203. https://doi.org/10.3897/zookeys.1041.63884