Is Nematocharax (Actinopterygii, Characiformes) a monotypic fish genus?
The combination of DNA barcodes and geometric morphometrics is useful to discriminate taxonomically controversial species, providing more precise estimates of biodiversity. Therefore, our goal was to assess the genetic and morphometric diversity in Nematocharax, a controversial monotypic and sexually dimorphic genus of Neotropical fish, based on sequencing of cytochrome c oxidase subunit I (COI) and morphometric analyses in seven populations of N. venustus from coastal rivers in Brazil. The average pairwise intrapopulation divergence in COI ranged from 0 to 2.2%, while the average pairwise interpopulation divergence varied from 0 to 7.5%. The neighbour-joining (NJ) tree resulted in five genetic groups (bootstrap ≥ 97%), which correspond to the five clusters delimited by the BIN System, GMYC, and bPTP, indicating that there might be at least five species (or OTUs) within Nematocharax. Morphometric differences among these genetic lineages were also identified. Apparently, sexual selection, restricted dispersal, and geographic isolation might have acted synergistically to cause the evolutionary split of populations. These data challenge the current view that Nematocharax is a monotypic genus inasmuch as evolutionarily significant units or even distinguished species were identified. Therefore, we recommend that the highly impacted coastal basins in northeastern Brazil should be prioritized in conservation plans.
a Department of Biological Sciences, Universidade Estadual do Sudoeste da Bahia, Av. José Moreira Sobrinho, s/n, Jequiezinho, 45206190, Jequié, Bahia, Brazil.
Silvia Britto
SB
Barreto
a Department of Biological Sciences, Universidade Estadual do Sudoeste da Bahia, Av. José Moreira Sobrinho, s/n, Jequiezinho, 45206190, Jequié, Bahia, Brazil.
Lorena Andrade
LA
Nunes
b Department of Zoology, Biosciences Institute, Universidade Estadual Paulista Júlio de Mesquita Filho, Av. 24-A, 1515, Bela Vista, 13506970, Rio Claro, São Paulo, Brazil.
André Teixeira
AT
da Silva
a Department of Biological Sciences, Universidade Estadual do Sudoeste da Bahia, Av. José Moreira Sobrinho, s/n, Jequiezinho, 45206190, Jequié, Bahia, Brazil.
Ricardo
R
Jucá-Chagas
a Department of Biological Sciences, Universidade Estadual do Sudoeste da Bahia, Av. José Moreira Sobrinho, s/n, Jequiezinho, 45206190, Jequié, Bahia, Brazil.
Débora
D
Diniz
c Coastal Studies Institute, Universidade Federal do Pará, Alameda Leandro Ribeiro, s/n, Aldeia, 68600000, Bragança, Pará, Brazil.
Iracilda
I
Sampaio
c Coastal Studies Institute, Universidade Federal do Pará, Alameda Leandro Ribeiro, s/n, Aldeia, 68600000, Bragança, Pará, Brazil.
Horacio
H
Schneider
a Department of Biological Sciences, Universidade Estadual do Sudoeste da Bahia, Av. José Moreira Sobrinho, s/n, Jequiezinho, 45206190, Jequié, Bahia, Brazil.
Paulo Roberto Antunes de Mello
PR
Affonso
D000818:Animals; D001938:Brazil; D060125:Characiformes / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics*; D002858:Chromium Alloys; D003035:Cobalt; D058893:DNA Barcoding, Taxonomic; D003576:Electron Transport Complex IV / Q000235:genetics; D023281:Genomics / Q000379:methods; D005843:Geography; D006239:Haplotypes; D010802:Phylogeny; D017422:Sequence Analysis, DNA
D002858:Chromium Alloys; C112499:phynox; D003035:Cobalt; D003576:Electron Transport Complex IV
COI; DNA barcoding; codage à barres de l’ADN; délimitation d’espèces; faune piscicole; geometric morphometrics; ichthyofauna; morphométrie géométrique; species delimitation