A new species of Astyanax Baird & Girard (Characiformes: Characidae) from western Chapada Diamantina, Bahia, Brazil

Abstract

A new species of Astyanax from the upper rio Paraguaçu basin, Chapada Diamantina, Bahia, Brazil, is described. Astyanax sincora shares characters currently used to define the Astyanax scabripinnis species complex, as highest body depth approximately at vertical through pectoral-fin midlength and a low number of branched anal-fin rays (13–17). It differs from its congeners by a combination of characters, including eight branched dorsal-fin rays, six branched pelvic-fin rays, presence of bony hooks in pectoral and anal fins of males, dark midlateral line or stripe initiating posteriorly to the vertically elongate humeral blotch, and by the presence of 30–35 scales in the median longitudinal series. The generic positioning of the new species and some polymorphic morphological characters in Astyanax are briefly discussed. The degree of completeness of the lateral line in Hyphessobrycon balbus is discussed. [Species Zoobank registration: urn:lsid:zoobank.org:pub:D708FE7E-3FB5-4729-B438-779717F7ED1A]

A new species of Astyanax (Characiformes: Characidae) from the rio de Contas basin, Bahia, Brazil

“…A total of 79 species of Astyanax was described in the last 20 years (Fricke et al, 2019), being one of the fish genera with higher expansion on its richness knowledge. Advances in alpha taxonomy of the ichthyofauna of the Brazilian coastal drainages contributed with 21 of those descriptions, being 11 from the Northeastern Mata Atlântica freshwater ecoregion (e.g., Rangel-Pereira, 2012;Birindelli et al, 2013;Lima et al, 2013;Mattos, Costa, 2018;Barreto et al, 2018;Burger et al, 2019); seven from rivers draining the Laguna dos Patos freshwater ecoregion (e.g., Lucena et al, 2013;Bertaco, Vigo, 2015), one species from the Tramandaí-Mampituba freshwater ecoregion (Bertaco, 2014), one species from the Ribeira de Iguape freshwater ecoregion (Silva et al, 2019), and one from the Southeastern Mata Atlântica freshwater ecoregion (Oliveira et al, 2013). Particularly to the NMAF, nine of the 11 species mentioned are from river basins inserted in the Bahia State, highlighting the rio Paraguaçu basin, with six described species, all of them apparently endemic to this basin (A. brucutu, A. epiagos, A. hamatilis, A. lorien, A. rupestris, and A. sincora).…”

Ficha de Astyanax sincora

“…Estados Bahia Biomas Caatinga Bacias Hidrográficas Sub-bacia Itapecuru-Paraguaçu Endêmica do Brasil: Sim Astyanax sincora é endêmica do Brasil e conhecida de pequenos tributários da bacia do alto rio Paraguaçu, no entorno da Chapada Diamantina, estado da Bahia (Burger et al, 2019;Silva et al, 2020).…”

“…Esses riachos têm profundidade máxima de um metro e largura máxima de 1,5 m, com substrato composto por lama, pedras ou areia e fluxo de água moderado. Astyanax sincora é aparentemente a única espécie de peixe que habita as localidades onde foi amostrada (Burger et al, 2019)…”

Freshwater fishes of the Bahia State, Northeastern Brazil

“…in taxonomic inventories (e.g., Sarmento-Soares et al 2009a, Cetra et al 2010, Burger et al 2011, Ramos et al 2014. Although numerous freshwater fish species from the Bahia river basins have been described in the last two decades (e.g., Bertaco & Lucena 2006, Ribeiro & Lucena 2006, Lima & Britski 2007, Benine et al 2007, Zanata & Camelier 2008, 2010, 2015, Bichuette et al 2008, Sarmento-Soares et al 2009b, Sarmento-Soares et al 2011, Ferreira et al 2014, Vari et al 2010, Bichuette & Rizzato 2012, Oliveira et al 2013, Sarmento-Soares & Martins-Pinheiro 2013, Camelier & Zanata 2014b, 2017, 2018, Mattos et al 2015, Peixoto & Wosiacki 2016, Zanata & Pitanga 2016, Zawadzki et al, 2017Barreto et al 2018, Mattos & Costa, 2018, Burger et al 2019, Lucena & Lucena 2019, ichthyological explorations continue to reveal unknown species, especially in small tributaries and in upper drainage areas. The increase in the number of species recently described from the São Francisco river basin has already been documented in the literature (see Alves et al 2011 andBarbosa et al 2017).…”