Integrative approach reveals a new species of Nematocharax (Teleostei: Characidae)

Abstract

An integrative approach based on morphological and multilocus genetic data was used to describe a new species of Nematocharax from the headwaters of the upper Contas River on the Diamantina Plateau, north‐eastern Brazil and to infer the relationships among evolutionary lineages within this fish genus. Multispecies coalescent inference using three mitochondrial and five nuclear loci strongly supports a basal split between Nematocharax venustus and the new species, whose distinctive morphological characters include absence of filamentous rays on pelvic fins of maturing and mature males, reduced anal‐fin lobe length and lower body depth. The unique morphological and genetic traits of the population from the upper Contas River were supported by previous reports based on cytogenetics, DNA barcode and geometric morphometrics, reinforcing the validation of the new species. The conservation status of this new species is discussed.

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).…”

“…Astyanax varii had been collected in six localities in the upper and lower rio de Contas basin. The main locality sampled in the upper rio de Contas, the Balneário Rio da Barra, is an artificial reservoir continually exploited for tourism as a bathing place (Barreto et al, 2018). Permanent anthropic perturbation such as loss of riparian vegetation and dams occurs in the main channel and some tributaries of rio de Contas (Cetra et al, 2010;Sarmento-Soares et al, 2016).…”

Drainage rearrangements and in situ diversification of an endemic freshwater fish genus from north‐eastern Brazilian rivers

“…Sequences were then aligned with the ClustalW Multiple Alignment tool (Thompson et al, 1994) in BioEdit 7.1.9 and deposited in GenBank (accession numbers MN011168-MN011188 and MN011203-MN011363). In addition to the 182 sequences generated specifically for this study, other 113 COI sequences of Nematocharax (including five additional localities) were downloaded from GenBank and BOLD (Barcode of Life Data Systems; http://www.bolds ystems.org/; accession numbers PIABA001-14-PIABA091-14, MG025937-MG025944, and MN011189-MN011202 from Barreto, Nunes, et al, 2016, Barreto et al, 2018, and Barreto et al, 2020 see Table S1 for further details), totaling 295 samples for the COI dataset (274 for N. venustus and 21 for N. varii).…”

“…Outstanding features of N. venustus include sexual dimorphism and morphological and genetic variation among its populations (Barreto, Cioffi, et al., 2016; Barreto, Nunes, et al., 2016; Menezes et al., 2015). By contrast, its only congener, Nematocharax varii , is known for only two nearby localities in a tributary of the Upper Contas River situated around 530 m elevation on the Chapada Diamantina highlands (Barreto et al., 2018). In this sense, reconstructing the evolutionary history of Nematocharax populations can help disentangle the role of drainage rearrangements on the evolution of freshwater fishes.…”

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).…”