A new species of Characidium (Characiformes: Crenuchidae) from the Chapada dos Veadeiros, Goiás, Brazil

Researchers have identified a new species of Characidium, a small freshwater fish belonging to the Crenuchidae family, from the Chapada dos Veadeiros National Park in Brazil. This discovery is significant due to its unique combination of morphological traits, including a scaleless isthmus paired with a single row of dentary teeth, and distinctive coloration marked by inconspicuous vertical bars forming square blotches along the body sides and a dark saddle-shaped mark at the dorsal-fin base. Osteological examination revealed additional unique features, such as fused anal-fin proximal radials contacting the branched third hemal spine, alongside an unusual variation in fin-ray counts among its congeners. The species was discovered in tributaries of the rio Tocantinzinho within the rio Tocantins basin, highlighting the rich biodiversity of this UNESCO World Heritage Site.

Melo, M. R. S., Bouquerel, B. B., Masumoto, F. T., França, R. S., & Netto-Ferreira, A. L. (2021). A new species of Characidium (Characiformes: Crenuchidae) from the Chapada dos Veadeiros, Goiás, Brazil. Neotropical Ichthyology, 19(2). https://doi.org/10.1590/1982-0224-2020-0152