Foul play? On the rapid spread of the brown shrimp Penaeus aztecus Ives, 1891 (Crustacea, Decapoda, Penaeidae) in the Mediterranean, with new records from the Gulf of Lion and the southern Levant

Specimens of the penaeid shrimp Penaeus aztecus, a West Atlantic species, were collected off Le Grau du Roi, Gulf of Lion, France, and off the Israeli coast, Levant Basin, Mediterranean Sea. This alien species has been previously recorded off Turkey, Greece, Montenegro and the Tyrrhenian coast of Italy. The species identity was confirmed based on morphological characters and by sequencing 406 nucleotides of the 16S RNA gene and 607 nucleotides of the COI. The 16S rRNA sequences of the specimens collected in Israel, France and Italy were identical, and exhibited three different COI haplotypes. The near-concurrent records from distant locations in the Mediterranean put paid to the premise that P. aztecus was introduced into the Mediterranean Sea in ballast waters. A more prudent proposition is that many of these populations issue from illegal introductions. Potential risks to native biodiversity and economic value are the likely competition with commercially important native prawns, co-introduction of pathogens and parasites, and risk of infecting penaeid populations elsewhere in the Mediterranean Sea with Erythraean alien disease agents previously limited to the Levant.