Discussion
Our results, based on a comprehensive ABFT genome-wide SNPs dataset (including larvae from the Slope Sea and spawning adults for the Mediterranean Sea and the Gulf of Mexico), confirmed that current ABFT populations originated from two ancestral populations as previously hypothesized (Rodríguez-Ezpeleta et al. 2019). Yet, they also revealed interbreeding in the Slope Sea and an eastern-western unidirectional gene flow that challenges the assumption of two isolated spawning areas. Moreover, the identification of previously unreported inter-specific introgressed regions in the ABFT nuclear genome and potentially adaptive markers within a newly discovered putative chromosomal inversion provided evidence to suggest that there have been recent changes in ABFT connectivity which holds significant implications for the conservation of the species.