DNA Barcoding unveils cryptic lineages of Hoplias malabaricus from Northeastern Brazil

Abstract

The trahira or wolf fish - Hoplias malabaricus- is a valid species, although recent cytogenetic and molecular studies have indicated the existence of a species complex. In this context, the present study analyzed the mitochondrial COI marker to determine the levels of genetic diversity of specimens from the Brazilian state of Maranhão, and verify the occurrence of distinct lineages within the study area. Samples were collected from the basins of the Turiaçu, Pindaré, Mearim, Itapecuru, and Parnaíba rivers. A 630-bp fragment was obtained from 211 specimens, with 484 conserved and 108 variable sites, and 60 haplotypes (Hd = 0,947; π = 0,033). The phylogenetic analyses indicated the existence of three distinct lineages of H. malabaricus from Maranhão. Genetic distances of 1.5-8.2% were found between all the populations analyzed, while the variation between haplogroups ranged from 2.1% to 7.7%. The AMOVA indicated that most of the molecular variation was found among groups, with high FST values. The high levels of genetic variability found in the present study are supported by the available cytogenetic data. These findings reinforce the need for the development of effective programs of conservation and management independently for each river basin, in order to preserve the genetic variability found in this taxon.

DNA barcoding and phylogeography of the Hoplias malabaricus species complex

“…Aguirre and colleagues 57 measured a maximum F ST divergence of 20% between H. microlepis populations from rivers and artificial impoundments in Ecuador. Due to its wide distribution range and sedentary habits, Hoplias species tend to exhibit high population genetic differentiation 9 , 58 .…”

4SpecID: Reference DNA Libraries Auditing and Annotation System for Forensic Applications

“…By the simple observation of the isolated subgraphs, species connected to more than one distant cluster may be the focus of further investigation to discover the reason behind the genetic divergence. Conversely, if more than one morphospecies are grouped in one single genetic cluster, three possibilities should be investigated: i) errors in the species identification have occurred; ii) a poor choice of parameters in the clustering algorithm that originated divergence distances not compatible to the actual species boundaries, and iii) the existence of an unique species designation for more than one species (cryptic species), which is a possibility of utmost relevance, namely, for conservation, deserving further investigation [15][16][17].…”