A taxonomic review of the species of CharaxScopoli, 1777 (Teleostei: Characidae: Characinae) with description of a new species from the rio Negro bearing superficial neuromasts on body scales, Amazon basin, Brazil

Abstract

The species of Charax were reviewed by Lucena (1987) who a little later (1989) added three new species to the genus. Examination of recently collected specimens from museum collections documented the more extensive geographic distribution for most species and revealed the existence of a new species in which superficial neuromasts were discovered and are herein described. These skin structures were also detected in C. metae Eigenmann, 1922. Anal-and pelvic-fin hooks previously observed only on the anal-fin of one species of the genus are described herein in some other species. Charax unimaculatus Lucena is considered a junior synonym of C. michaeli Lucena. All the species are redescribed and the new species described.As espécies de Charax foram revistas por Lucena (1987), que pouco depois (1989) acrescentou três espécies novas ao gênero. O exame de exemplares recentemente coletados e depositados em coleções de vários museus possibilitaram a extensão da distribuição geográfica da maioria das espécies e revelou a existência de uma espécie nova, na qual foram descobertos neuromastos superficiais, caracterizados neste trabalho. Estas estruturas da pele também foram detectadas em Charax metae Eigenmann, 1922. Ganchos das nadadeiras anal e pélvica, anteriormente observados apenas na nadadeira anal de uma das espécies do gênero, são agora descritos em algumas outras espécies. Charax unimaculatus Lucena é considerada sinônimo júnior de C. michaeli Lucena Todas as espécies são redescritas, juntamente com a descrição da espécie nova.

A new species of Charax (Ostariophysi, Characiformes, Characidae) from northeastern Brazil

“…Counts and measurements were taken according to Fink and Weitzman (1974), Menezes and Weitzman (1990) and Menezes and Lucena (2014), on the left side of specimens whenever possible, using a dig ital caliper with precision of 0.01 mm. Measurements are given as a percentage of standard length (SL), except for subunits of the head, which are given as a percentage of head length (HL).…”

“…Diagnosis was made based on a unique combination of character states, according to Davis and Nixon (1992). Information about congeners was based on both comparative material and literature (e.g Lucena 1987, Mattox and Toledo-Piza 2012, Menezes and Lucena 2014 …”

“…Characidae is the most species-rich family of Characiformes, comprising about 165 genera and more than 1.150 species, distributed along the river systems between southwestern Texas and Mexico in North America and Patagonia in South America (Nelson et al 2016;Eschmeyer et al smaller isolated river basins draining the Guiana Shield, and in the Lagoa dos Patos system, and other coastal lagoons of southern Brazil (Menezes and Lucena 2014).…”

“…The distribution of the genus is mainly concentrated in central and northern South America; there is no record for eastern Brazil and none of the valid species was assigned for the coastal river basins of northeastern Brazil by the recent taxonomic revision of the genus (see Menezes and Lucena 2014). However, some records of Charax for the coastal river basins of northeastern Brazil were made before the taxonomic revision made by Menezes and Lucena (2014): Martins and Oliveira (2011) recorded C. gibbosus for the Rio Mearim basin; Barros et al (2011) recorded Charax sp.…”

“…However, some records of Charax for the coastal river basins of northeastern Brazil were made before the taxonomic revision made by Menezes and Lucena (2014): Martins and Oliveira (2011) recorded C. gibbosus for the Rio Mearim basin; Barros et al (2011) recorded Charax sp. for the Rio Itapecuru basin; Martins and Oliveira (2011) recorded Charax sp.…”