A new species of Moenkhausia Eigenmann (Characiformes: Characidae) from the rio Xingu basin, Brazil

Abstract

A new species of Moenkhausia Eigenmann (Characiformes: Characidae) from the rio Xingu basin, Brazil Manoela M. F. Marinho A new species of Moenkhausia from the upper rio Xingu basin is described. Moenkhausia eurystaenia is distinguished from all congeners, except M. heikoi and M. phaeonota, by the presence of a dark, broad longitudinal stripe from the opercle to the end of caudal peduncle. The new species is distinguished from M. heikoi mainly by having 18-21 branched anal-fin rays (vs. 24-26) and the absence of a round blotch at the end of the caudal peduncle (vs. present). Moenkhausia eurystaenia can be distinguished from M. phaeonota mainly by the anterior portion of longitudinal band darker at horizontal septum (vs. darker below horizontal septum), the deep dark pigmentation along horizontal septum extending anteriorly up to humeral region (vs. extending up to vertical through pelvic-fin origin), number of vertebrae 34 (vs. 36-37), and others additional measurements.Uma espécie nova de Moenkhausia da bacia do alto rio Xingu é descrita. Moenkhausia eurystaenia distingue-se de todas as congêneres, exceto M. heikoi e M. phaeonota, pela presença de uma faixa longitudinal larga e escura que se estende do opérculo ao pedúnculo caudal. A espécie nova distingue-se de Moenkhausia heikoi principalmente por apresentar 18-21 raios ramificados na nadadeira anal (vs. 24-26), e ausência de uma mácula circular no final do pedúnculo caudal (vs. presença). Moenkhausia eurystaenia distingue-se de M. phaeonota principalmente pela porção anterior da faixa longitudinal ser mais escura no septo horizontal (vs. mais escura abaixo do septo horizontal), pigmentação profunda e escura ao longo do septo horizontal se estendendo até a região umeral (vs. se estendendo até a vertical que passa pela origem da nadadeira pélvica), 34 vértebras (vs. 36-37), e outras medidas adicionais.

Moenkhausia rubra, a new species from rio Juruena, upper rio Tapajós basin, Brazil (Characiformes: Characidae)

“…The genus Moenkhausia Eigenmann currently comprises over seventy valid species (Bertaco et al, 2011a(Bertaco et al, , 2011bMariguela et al, 2013) presenting a wide variation in overall shape and pigmentation patterns (Benine et al, 2004), many of which have been described recently (e.g., Benine et al, 2009;Zanata et al, 2009;Marinho, 2010;Marinho & Langeani, 2010;Sousa et al, 2010;Bertaco et al, 2011aBertaco et al, , 2011b. The genus is widely distributed in South America, being present in coastal drainages of the Guyanas, as well as in the río Orinoco, rio Amazonas, rio Tocantins and Araguaia, rio São Francisco, rio Paraná-Paraguay, and Brazilian eastern drainages (Lima et al, 2003).…”

New species of Moenkhausia Eigenmann (Ostariophysi: Characidae) from the upper rio Tocantins basin in Central Brazil

“…The genus Moenkhausia Eigenmann is a speciose group of characid fishes comprising 71 valid species widespreadly distributed in the Neotropical Cis-Andean river basins, except for those in Patagonia (Lima et al, 2003;Eschmeyer & Fricke, 2010;Marinho, 2010). None of the diagnostic characters presently used to recognize Moenkhausia is unique to the genus, e.g.…”

Hemigrammus ataktos: a new species from the rio Tocantins basin, central Brazil (Characiformes: Characidae)

“…Pending further studies on the relationships of these genera, we tentatively assign the new species to Hemigrammus rather than Moenkhausia, because most of the examined specimens fit the traditional definition of the former genus. The new species can be distinguished from all species of Moenkhausia, except M. eurystaenia Marinho, 2010, M. heikoi Géry & Zarske, 2004, and M. phaeonota Fink, 1979, by having a dark midlateral stripe from opercle to caudal peduncle (vs. stripe, when present, originating approximately at vertical through dorsal-fin origin). It is distinguished from Moenkhausia eurystaenia, M. heikoi and M. phaeonota by having elongate anteriormost dorsal and anal-fin rays on mature males (vs. not elongate).…”

“…This is the case for the most diverse characid genera, such as Hemigrammus (54 species), Hyphessobrycon (130 species) and Moenkhausia (76 species) (Weitzman & Fink, 1983;Lima et al, 2003;Eschmeyer, 2013). According to this classification, which is still being used to classify species (e.g., Carvalho et al, 2010;Marinho, 2010;Sousa et al, 2010;Bertaco et al, 2011aBertaco et al, , 2011bIngenito et al, 2013), the genus Hemigrammus is diagnosed from Hyphessobrycon uniquely by the presence of small scales covering the proximal portion of the caudal-fin lobes (vs. absence), and from Moenkhausia by having an incompletely pored lateral line (vs. completely pored lateral line). Based on this system, part of the specimens of the new species would fit into Hemigrammus, whereas part would be best identified as Moenkhausia.…”