Abstract
Crabs are the most widely studied marine crustaceans due to their high economic value, ecological significance, and worldwide range in the subtropics and tropics zones. In this study, we adopted a molecular barcoding approach for rapid identification of blue crab species by sequencing the mitochondrial cytochrome c oxidase subunit I gene (COI), which has previously been used for phylogenetic analysis in wide taxonomic groups, and particularly for Crustaceans. The results indicated the evidence of Callinectes sapidus and Portunus pelagicus in different localities along Tunisian coast. Data were confirmed by BLAST analysis (Basic Local Alignment Tool) and phylogenetic trees. The molecular identification showed the ability of the COI region to differentiate between two similar blue crab species, Portunus segnis and Portunus pelagicus, which were confused by morphological analysis. The adoption of this protocol may be useful in revealing the biogeography of these invasive species across Mediterranean and to support the authentication of crab-meat processed products, according to the normative control.