title: Probing diversity in freshwater fishes from Mexico and Guatemala with DNA barcodes.
abstract: The freshwater fish fauna of Mexico and Guatemala is exceptionally diverse with >600 species, many endemic. In this study, patterns of sequence divergence were analysed in representatives of this fauna using cytochrome c oxidase subunit 1 (COI) DNA barcodes for 61 species in 36 genera. The average divergence among conspecific individuals was 0.45%, while congeneric taxa showed 5.1% divergence. Three species of Poblana, each occupying a different crater lake in the arid regions of Central Mexico, have had a controversial taxonomic history but are usually regarded as endemics to a single lake. They possess identical COI barcodes, suggesting a very recent history of isolation. Representatives of the Cichlidae, a complex and poorly understood family, were well discriminated by barcodes. Many species of Characidae seem to be young, with low divergence values (<2%), but nevertheless, clear barcode clusters were apparent in the Bramocharax-Astyanax complex. The symbranchid, Opisthernon aenigmaticum, has been regarded as a single species ranging from Guatemala to Mexico, but it includes two deeply divergent barcode lineages, one a possible new endemic species. Aside from these special cases, the results confirm that DNA barcodes will be highly effective in discriminating freshwater fishes from Central America and that a comprehensive analysis will provide new important insights for understanding diversity of this fauna.
authors.affiliation: El Colegio de la Frontera Sur, Av. Centenario km 5.5, Chetumal 77014, Quintana Roo, México. mvaldez@ecosur-qroo.mx
authors.forename: M
authors.initials: M
authors.lastname: Valdez-Moreno
authors.forename: N V
authors.initials: NV
authors.lastname: Ivanova
authors.forename: M
authors.initials: M
authors.lastname: Elías-Gutiérrez
authors.forename: S
authors.initials: S
authors.lastname: Contreras-Balderas
authors.forename: P D N
authors.initials: PD
authors.lastname: Hebert
mesh_terms: D000818:Animals; D058893:DNA Barcoding, Taxonomic; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D005399:Fishes / Q000145:classification / Q000235:genetics*; D005618:Fresh Water; D014644:Genetic Variation; D006166:Guatemala; D008800:Mexico; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV