A new species of Characidium (Characiformes: Crenuchidae) from the upper rio São Francisco basin, Minas Gerais, Brazil

Abstract

Characidium cacah, new species, apparently endemic to the rio das Velhas sub-basin, upper rio São Francisco basin, Brazil, is described. The new species is easily distinguished from congeners, except C. chicoi, C. helmeri, C. mirim, C. nana, C. nupelia, C. stigmosum and C. xavante, by having an incomplete lateral line and for lacking an adipose fin. The new species can be diagnosed from the aforementioned species by a series of characters, including the presence of 12 circumpeduncular scales, the isthmus completely scaled, a thin inconspicuous or dashed midlateral dark stripe, the absence of a conspicuous peduncular blotch, and humeral blotch and basicaudal spot variably marked.

Ficha de Characidium cacah

“…Biomas Cerrado Bacias Hidrográficas Sub-bacia São Francisco Alto Distribuição Endêmica do Brasil: Sim Characidium cacah é descrita da drenagem do rio Cipó, um afluente da sub-bacia do rio das Velhas, na bacia do rio São Francisco, no estado de Minas Gerais, Brasil (Zanata et al, 2020).…”

“…Ambos possuem águas escuras, fundo lamacento e cercadas por pastagens de gado e macrófitas marginais. Nestes locais lênticos e rasos (0,2-1,0 m de profundidade), apenas pequenos juvenis de C. cacah foram capturados (17,9-27,9 mm SL), enquanto os espécimes maiores foram amostrados apenas nos sítios lóticos (Zanata et al, 2020).…”

A new rheophilic South American darter (Crenuchidae: Characidium) from the rio Juruena basin, Brazil, with comments on morphological adaptations to life in fast‐flowing waters

“…Thirty new species were added to the genus after the most comprehensive phylogenetic hypothesis proposed by Buckup (1993a), and the interspecific phylogenetic relationships of these more recently described species have not yet been addressed ( e.g ., Agudelo‐Zamora et al ., 2020; Zanata et al ., 2018, 2020; Zanata & Ohara, 2015). One of the clades of Characidium recognized by Buckup (1993a) is typical of highly specialized rheophilic species, the C3 clade, composed of Characidium crandellii Steindachner 1915 and Characidium declivirostre Steindachner 1915.…”