New Records of Callinectes sapidus (Crustacea, Portunidae) from Malta and the San Leonardo River Estuary in Sicily (Central Mediterranean)

Abstract

The current study provides new data on the known records of the Atlantic blue crab, Callinectes sapidus Rathbun, 1896, from the Maltese Islands through two ovigerous female specimens collected from Salini (Malta), a Natura 2000 site, in August 2020. Additional new records of the species were also presented from the San Leonardo River estuary, Syracuse (Sicily, Italy), in August 2022. The specimens collected from both Malta and Sicily were identified using both morphological and molecular analyses. The latter has shown that all the specimens analysed share their mitochondrial DNA barcode region with the most recorded haplotype of the same species from the Mediterranean Sea. Knowing the new distribution and range expansion records of alien species is important for the continuous monitoring of marine alien species, which is essential for the implementation of the best possible mitigation measures. This is especially relevant for C. sapidus, as it is considered one of the worst invaders of the Mediterranean Sea. Therefore, given that this alien species is edible, fishing for it may allow some control over its population size and further expansion. Knowing its distribution is crucial to inform fishers about its exact location, making such a mitigation measure more effective.