Lebiasina yepezi, a new Lebiasininae (Characiformes: Lebiasinidae) from the Serra Parima-Tapirapecó mountains

Abstract

Lebiasina yepezi, a new Lebiasininae with a conspicuous color pattern, is described. The new species is endemic of the headwaters of the rio Negro, rio Branco, and rio Orinoco in the Serra Parima-Tapirapecó Mountains, at the border of Brazil and Venezuela. The new species is readily distinguished from all other Lebiasininae by the presence of four black longitudinal stripes on the trunk, and the triangular shaped dorsal surface of the mesethmoid, lacking lateral projections. The unusual color pattern is contrasted with those of other lebiasinin, as well as members of the pyrrhulinin genus Nannostomus. A close relationship between Lebiasina yepezi and the Gran Sabana (Venezuela) species is suggested based in color pattern features. The present contribution corresponds to a further refutation of the type locality of L. intermedia, as suggested on its description, since Lebiasinins, except L. bimaculata, L. boruca, and L. festae, do not occur in low land waters.Lebiasina yepezi, um novo Lebiasininae com um conspícuo padrão de colorido, é descrito. A nova espécie é endêmica das cabeceiras do rio Negro, rio Branco e rio Orinoco, na Serra Parima-Tapirapecó, ao longo da fronteira entre Brasil e Venezuela. A nova espécie é prontamente diferenciada das demais espécies pela presença de quatro faixas longitudinais escuras ao longo do corpo, e a superfície dorsal do mesetmoide com o formato triangular, não apresentando projeções laterais. O padrão de colorido incomum é comparado com o dos demais Lebiasininae e também com o dos Pyrrhulininae do gênero Nannostomus. Uma próxima relação é proposta entre Lebiasina yepezi e as espécies da Gran Sabana (Venezuela) com base em caracteres de colorido. A presente contribuição corresponde a mais uma refutação da localidade-tipo de L. intermedia conforme sugerida na descrição daquela espécie, uma vez que os lebiasiníneos, com exceção de L. bimaculata, L. boruca e L. festae, não ocorrem em rios de terras baixas.

A new sexually dichromatic miniature Hyphessobrycon (Teleostei: Characiformes: Characidae) from the Rio Formiga, upper Rio Juruena basin, Mato Grosso, Brazil, with a review of sexual dichromatism in Characiformes

“…The Lebiasinidae are well known for exhibiting several sexually dimorphic characteristics, related to the standard length (Taphorn & Lilyestrom, 1980), anal-fin morphology (Fernandez & Weitzman, 1987;Netto-Ferreira et al, 2011), colour pattern (Weitzman & Cobb, 1975;Zarske, 2009) and even behaviour (Krekorian & Dunham, 1972;Menezes & Vazzoler, 1992). References to sexual dichromatism in lebiasinids are more abundant than those of remaining Characiformes.…”

New species of Pyrrhulina (Teleostei: Characiformes: Lebiasinidae) from the eastern Amazon, Pará, Brazil

“…Counts and measurements follow those proposed by Fink, Weitzman (1974) and Netto-Ferreira et al (2011). All measurements were made point-to-point using calipers with 0.1 mm precision.…”

“…Counts were made from the left side of specimens whenever possible. Vertebrae of the Weberian apparatus were considered four precaudal elements, transitional vertebrae (sensu Weitzman, 1962) were included in the count of precaudal vertebrae, and the fused PU1+U1 of the caudal region was counted as a single element (Netto-Ferreira et al, 2011). Patterns of circuli and radii were observed on scales sampled from the region between the lateral line series and the dorsalfin origin.…”

“…Ventral portion of head with few, scattered chromatophores. Mid-dorsal, first and second longitudinal series of scales with light brown pigmentation, becoming -Ferreira et al, 2011;Netto-Ferreira, Marinho, 2013), in which the anal-fin rays and all intervening membranes are distinctly thicker and longer than in females, ultimately resulting in broader anal fins in male specimens (Marinho, Menezes, 2017). Male specimens possess more maxillary teeth than females (11-18 vs. 7-10, respectively).…”

“…The family Lebiasinidae includes 74 small species of fishes (16.0 mm SL up to maximum 250.0 mm SL) endemic to the Neotropical region (Weitzman, Weitzman, 2003;Netto-Ferreira et al, 2011;Fricke et al, 2019). Within Lebiasinidae, the subfamily Pyrrhulininae includes 45 valid species (Fricke et al, 2019) allocated among four genera, which are defined mainly by synapomorphies related to the oral area and cephalic laterosensory canals (Netto-Ferreira, 2010).…”