Redescription of Hemibrycon jelskii, with comments on H. huambonicus, and description of five new species from the Amazon River basin (Characiformes: Characidae: Stevardiinae)

Abstract

We examined 407 specimens and images of Hemibrycon jelskii1 and H. huambonicus2 (31 types and 376 non-types) and analyzed them using four analytical approaches: (i) traditional morphometry, (ii) morpho-geometric analysis, (iii) comparison of meristics (scales and fin rays), and (iv) comparison of color and pigment patterns. Our study determined that only 18 individuals from the 28 type specimens have characters that correspond with the description of H. jelskii. Hemibrycon jelskii was described from specimens of unknown, possibly multiple origins, raised in aquaria by Konstanty Jelski. A high morphological disparity exists among the individuals that make up the type series, so it is assumed that they are different forms, probably from different locations in the Huambo River drainage, in the Peruvian Andes. The reported variation in morphological and pigmentation characters observed in the type specimens is due to two main facts: 1) the incorrect taxonomic identification of one lot, which is a curimatid, Cyphocharax sp., and 2) the probability that specimens of the type series were collected from different localities. In addition, morphological differences were observed in the type series of H. huambonicus, consisting of three specimens in two lots. Our study also revealed five new species of Hemibrycon described herein.