Genome-wide SNPs reveal complex patterns of introgressive hybridization between Carcharhinus tilstoni and Carcharhinus limbatus blacktip sharks.

The objectives of this study were (1) to develop novel genome-wide nuclear markers using a Reduced Representation Genotyping by Sequencing approach (RRGS) to evaluate the level of admixture between the sympatric populations of C. tilstoni and C. limbatus of the eastern coast of Australia; (2) to identify a minimum number of diagnostic single nucleotide polymorphisms (SNPs) with maximum power to delineate the hybrid classes present between the two blacktip species for application in fisheries enforcement and forensic cases; (3) to compare the power and resolution that diagnostic markers provide for hybrid class delineation with previous results that used mtDNA, microsatellite markers and pre-caudal vertebrae count discordance.