Presence of Amphibalanus eburneus (Crustacea, Cirripedia) in Gomishan Wetland: Molecular and morphological evidence of a new introduction to the southern Caspian Sea

The barnacle Amphibalanus eburneus (Gould, 1841), native to the northwest Atlantic Ocean, became nearly cosmopolitan due to extensive shipping activities. In the Caspian Sea, A. eburneus have been reported solely from Azerbaijan and Turkmenistan. The current study provides robust evidence of its occurrence in Iran. We observed that the previously vacant niche on the hard substrates bordering a shrimp farm in Gomishan Wetland, southern Caspian Sea, is now occupied by A. eburneus. The identity of the species was confirmed by both morphological and molecular approaches. Massive development of this (previously thought) brackish species in saline waters (33–57 psu) of the Gomishan Wetland demonstrates the high invasion potential of the species. Although it seems that this introduction has had no impact so far, it can be projected that the entire coastline of the southern Caspian Sea might be colonized by A. eburneus, which may outcompete the native fauna of the area in the future.