Genetic Diversity, Connectivity and Demographic History of the Small Red Scorpionfish Scorpaena notata at a Small-Scale in the Balearic Islands (Western Mediterranean)

This study analyzes for the first time the genetic diversity, connectivity, and evolutionary dynamics of the small red scorpionfish (Scorpaena notata) in the Balearic Islands based on mitochondrial DNA. Nucleotide diversity of the Cytochrome c oxidase subunit I (COI) gene was found to be low compared to other commercial fish species, suggesting that fishing may be impacting the population despite being a by-catch species. In contrast, the Control Region (CR) showed higher genetic variability. Demographic history analyses suggest that S. notata underwent a population expansion during the Pleistocene, possibly driven by sea-level changes. Genetic structure analyses (Fst and AMOVA) indicated genetic homogeneity and high connectivity among the Balearic Islands’ population, likely facilitated by its passive dispersion with pelagic eggs and larvae and the oceanographic conditions of the region. Our results indicate that the entire Balearic Islands should be considered as a unique Management Unit, although its potential relation to other nearby areas, such as the Iberian Peninsula, should also be studied.