Disentangling the controversial identity of the halfbeak stock ( Hemiramphus brasiliensis and H. balao) from northeastern Brazil using multilocus DNA markers.

Reliable biological identification is essential for effective management programs for fishery resources. In many cases, individuals of species with overlapping features and/or subtle morphological differences can be misidentified by traditional taxonomic procedures. The conservation status (i.e., genetic diversity) of commercial fishery stocks of the Southern Atlantic are in general poorly understood. The halfbeak populations found off the coast of northeastern Brazil represent a suitable model for testing controversial identifications, given that the two local species ( Hemiramphus brasiliensis and H. balao) not only present very subtle morphological differences, but are also harvested intensively. The present study examined the potential occurrence of the two species off the coast of the Brazilian state of Pernambuco using a multilocus DNA approach, which also provided insights into the conservation status of these stocks in relation to the genetic variation found in both mitochondrial and nuclear regions, analyzed by molecular systematics and population genetics parameters. The results indicated the presence of only one halfbeak species in the region, reinforced by phylogenetic relationships and population genetics in both mitochondrial and nuclear loci. The conservation status of the stocks in terms of their genetic diversity appears to be good despite the intense exploitation. The results of this study provide a new perspective for the conservation and management of this fishery resource, particularly given the fact that the intensive exploitation over the last five decades appears to have impacted a single species, rather than two. [ABSTRACT FROM AUTHOR]