Study of genetic diversity and kinship analyzes in rays of the genus Narcine (Chondrichthyes: Narcinidae) in the western Atlantic Ocean using SNPs molecular markers

Abstract

Overfishing imposes changes in the life strategies of organisms, especially elasmobranchs (sharks and rays) that have biological characteristics that make them vulnerable to mortality caused by human effects. Understanding the structure of populations becomes na importante tool for conservation and management of stocks, which requires a broad knowledge of genetic, biogeographic, distribution and occurrence of species. The genus of rays Narcine (family Narcinidae) is currently formed by 16 species that are popularly called electric rays, which, in general, are widely threatened by unintentional fishing, including the species N. brasiliensis (near threatened) and N. bancroftii (stable). Trawl fishing has a high number of incidental catches of these species, however the individuals are discarded for not having commercial importance. In this context, the main objective of the present study is to develop Single Nucleotide Polymorphism (SNPs) markers to investigate the species of rays of the genus Narcine off the coast of Brazil and their populations, in addition to verifying the occurrence of polyandry in the group. To carry out this research we had 314 samples distributed in the species N. brasiliensis, N. bancroftii and Narcine sp obtained from different locations on the coast of Brazil. The samples were stored in vials with 95% ethanol for later carrying out the steps of DNA extraction, identification (DNA barcode) and analysis of SNPs, obtained with next generation sequencing (NGS), to test hypotheses of the existence of three species of rays of the genus Narcine and the occurrence of polyandry. With these data, we intend to contribute to the knowledge of the diversity and conservation of electric rays on the coast of Brazil.