DNA barcoding reveals high levels of genetic diversity in the fishes of the Itapecuru Basin in Maranhão, Brazil

Abstract

ABSTRACT. DNA barcoding is a useful complementary tool for use in traditional taxonomic studies due to its ability to detect cryptic species, and may be particularly efficient in the identification of fish species. The fish fauna of the Itapecuru River represents an important fishery resource in the Brazilian State of Maranhão, although it is currently suffering increasing degradation as a result of anthropogenic impacts. Therefore, DNA barcoding was used in the present study to identify fish species and establish a database of the rich freshwater fish fauna of Maranhão. A total of 440 specimens were analyzed, corresponding to 64 species belonging to 59 genera, 31 families, and 10 orders. Overall, 92.19% of these species could be identified by DNA barcoding, and were characterized by low levels (average 0.80%) of intra-specific divergence. However, five species (Anableps anableps, Gymnotus carapo, Sciades couma, Pseudauchenipterus nodosus, and Leporinus piau) presented values of mean genetic divergence above 3%, indicating the existence of cryptic diversity in these fishes. The DNA barcoding approach permitted the analysis of a large number of specimens and facilitated the discrimination and identification of closely related fish species in the Itapecuru Basin.

DNA barcoding analysis of Gymnotus species in two Neotropical river basins

“…Our results provide further evidence of the complexity of the Gymnotus genus, particularly, that of the carapo complex, evidencing cryptic diversity, which cannot be measured by morphological taxonomic characters. This cryptic diversity in neotropical Gymnotus was observed in earlier studies (Henriques, ; Nascimento et al, ).…”

DNA barcoding fishes from the Congo and the Lower Guinean provinces: Assembling a reference library for poorly inventoried fauna

“…Other overlooked taxa may be distinguished by DNA barcode divergences of 0.7%–3.8% within nine morphospecies present in a single province. The contribution of DNA barcoding for the detection of new taxa was acknowledged in most DNA barcoding campaigns focusing on large river basins (Decru et al, ; Hubert et al, ; Nascimento et al, ; Pereira, Pazian, Hanner, Foresti, & Oliveira, ; Shen, Guan, Wang, & Gan, ). Multiple lineages were suspected within Enteromius miolepis on the basis of DNA barcodes.…”

Freshwater fishes of the Parque Nacional dos Lençóis Maranhenses and adjacent areas

“…The 49 species herein recorded represent three times the number of freshwater species (13) reported by Matavelli et al (2015) for the Munim, Parnaíba and other smaller coastal river basins, as well as more than twice the number of species (20) reported by Ribeiro et al (2014) for the Munim river basin. It has just 11 species less than the number of species (60) reported by Soares (2013) for the Mearim river basin; just 20 species less than the number of species (69) reported by Barros et al (2011), and 15 species less than the survey (64) performed by Nascimento et al (2016), respectively, for the Itapecuru river basin, one of the major coastal river basins of this ecoregion; and just 16 species less than the inventory (65) published by Melo et al (2016) for the Parnaíba river basin, the major coastal river basin of the Maranhão-Piauí ecoregion and one of the main river basins of Brazil. The two surveys including more species recorded from coastal river basins of the Maranhão state were the works published by Ramos et al (2014) for the Parnaíba river basin, and the survey provided by Castro & Dourado (2011) for the Mearim, Pindaré, Pericumã and upper Turiaçu river drainages, including 146 and 109 species, respectively.…”