Hemigrammus tocantinsi: a new species from the upper rio Tocantins basin, Central Brazil (Characiformes: Characidae)

Researchers have identified and described Hemigrammus tocantinsi, a new species of fish from the upper Rio Tocantins basin in Central Brazil. This discovery is notable for several distinguishing features: it possesses 15-17 branched anal-fin rays, a longitudinal stripe that narrows anteriorly and widens posteriorly, and one or two maxillary teeth. The study also highlights sexual dimorphism in this species, characterized by differences in coloration, adipose-fin origin, body measurements, and the presence of bony hooks in the anal and pelvic fins of males. The research contributes to the understanding of biodiversity in the Cerrado Protected Areas, specifically within Chapada dos Veadeiros and Emas National Parks, which are part of UNESCO World Heritage Sites.

Carvalho, F. R., Bertaco, V. A., & Jerep, F. C. (2010). Hemigrammus tocantinsi: a new species from the upper rio Tocantins basin, Central Brazil (Characiformes: Characidae). Neotropical Ichthyology, 8(2), 247–254. https://doi.org/10.1590/s1679-62252010000200002