The establishment of the northern brown shrimp Penaeus aztecus Ives, 1891 in the central Mediterranean : new fisheries records from Malta and the southern shores of Sicily

Abstract

The northern brown shrimp, Penaeus aztecus, a penaeid species native to the western Atlantic, has rapidly expanded across the Mediterranean since its first record in Turkey (2009). Here, we report data supporting the establishment of P. aztecus in Maltese waters and along the southern shores of Sicily in the central Mediterranean, following the recent first record of the species from the same waters, suggesting an aggressive expansion by the species within the region. On 16th December 2024, two P. aztecus specimens were captured in Marsaxlokk Bay at a depth of 2 m using a trammel net. Subsequently, new records were documented in other Maltese localities by professional fishers, as well as in Porto Santo Stefano (northern Tyrrhenian Sea) and southeastern Sicily (Ionian Sea), confirming the species’ continuous and widespread expansion. In several cases, P. aztecus cooccurred with the native and congeneric P. kerathurus, raising concerns about potential inter-specific competition. The species is already exploited in Turkey and Italy, yet its ecological and economic impacts remain uncertain. Further studies are needed to assess its interactions with native species and fisheries.