Genetic Population Structure and Diversity of the Whitetail Dogfish Squalus albicaudus (Chondrichthyes, Squaliformes) along the Brazilian Coast as Identified by SNP Markers

The shark Squalus albicaudus, categorized by the International Union for Conservation of Nature red list as Data Deficient due to lack of minimal information for classification, is distributed throughout the Brazilian coast. High pressures such as overfishing and anthropic activities, as well as certain biological characteristics, including k strategists, comprise influential shark stocks reduction agents. However, genetic diversity, population structure, connectivity, and effective population size data are still limited for S. albicaudus, indicating the need for further studies. In this context, the genetic variability and population structure of S. albicaudus were investigated herein to test for panmixia. Samples were obtained from coasts of the Brazilian states of Pernambuco, Rio de Janeiro, and São Paulo along the species distribution range, and single nucleotide polymorphisms (SNPs) were assessed by the ddRADseq method. The findings revealed a panmitic S. albicaudus population, explained by certain life strategies, such as polyandry and migratory behavior. Based on the genomic findings reported herein, a single S. albicaudus population should be considered in the study area, indicating the need for specific management and conservation plans at the regional scale.