A new species of Chrysobrycon (Characiformes, Characidae, Stevardiinae) from the Amazon River basin in Colombia, with a new diagnostic characteristic for the genus

Abstract

Chrysobrycon mojicai sp. nov. is described from forest streams that are part of the Amazon River basin in Colombia. It is distinguished from all congeners by having most of the maxillary teeth with distal tips lateroventrally curved (v. teeth straight along their lengths) and a greater number of dentary teeth (20–27 v. 11–19, except in Chrysobrycon yoliae). The posterior margin of the ventral process of the quadrate does not reach the vertical through the posterior margin of the symplectic and these features differentiate C. mojicai from Chrysobrycon myersi and C. yoliae (v. posterior margin of ventral process of quadrate reaching vertical through posterior margin of symplectic). In species of Chrysobrycon, the frontals are extensively contacting each other along the midline, resulting in an absent frontal fontanel and a reduced parietal fontanel. This extensive contact between the frontals modifying the fontanels is a condition rarely found within the Stevardiinae and hence is proposed as an additional diagnostic characteristic for the genus. An updated identification key for all Chrysobrycon species is provided.