Genetic diversity and multiple paternity analysis in sharks of the genus Squalus (Chondrichthyes: Squalidae) using of SNPs

Abstract

Overfishing imposes changes in the life strategy of organisms, especially elasmobranchs (sharks and rays). Thus, understanding the structure of populations becomes an important tool for conservation and management of stocks, which requires a broad knowledge on genetic, biogeographic, distribution and occurrence of species. The identification of stocks genetically differentiated and adapted to their habitat represent a fundamental point for the management of the species. Sharks of de genus Squalus (Family Squalidae) are popularly called dogfish. This genus constitutes one of the most problematic groups of sharks taxonomically, due to the great morphological similarity among the species, where many researchers believe that in this group there are errously described taxa. In the Atlantic Ocean there are about 11 species of the genus Squalus, however, in the Brazilian coast these species were never genetically identified or had their populations analyzed. Data scarcity and taxonomic confusion reflect the current status of the IUCN Red List (International Union for Conservation of Nature), where most Squalus species are listed as "insuficiente data" or "nonexistent". In this context, the main objective of this work is to develop SNPs (Single Nucleotide Polymorphism) markers for population studies in the identified species, as well as multiple paternity analysis. To perform this research we have 60 litters, ranging from 2 to 12 pups/mother, totaling 283 samples distributed in the species S.cubensis, S.clarkae and S.acanthias, obtained from different localities on the coast of Argentina and Brazil. The samples were stored in 95% etanol flasks for further DNA sequencing, identifications and analysis of SNPs obtained with new generation sequencing (NGS), to test hypotheses about population relations (including isolation), in which it will contribute for the knowledge of the diversity and conservation of dogfish sharks in the Atlantic Ocean, allowing the study of multiple paternity of these species. (AU)