MASSIVE SETTLEMENTS OF THE ALIEN OYSTER ISOGNOMON BICOLOR, RAPIDLY SPREADING IN MEDITERRANEAN

Ivan Angelo Gatì; Miriana Ragusa; Michela D'alessandro; Salvatore Giacobbe; Valentina Esposito

Ivan Angelo Gatì, Dr. Messina University,ChiBioFarAm Department https://orcid.org/0009-0000-9818-3965
Miriana Ragusa, Dr. Messina University,ChiBioFarAm Department
Michela D'alessandro, Dr. https://orcid.org/0000-0001-7638-7027
Salvatore Giacobbe, Dr. Messina University,ChiBioFarAm Department https://orcid.org/0000-0002-4619-4862
Valentina Esposito, Dr. National Institute of Oceanography and Applied Geophysics-OGS https://orcid.org/0000-0001-7595-8369

Keywords: Invasive species, Spreading, Biomass, Population density, Mediterranean sea

Abstract

This paper reports updated records of the tropical West Atlantic oyster Isognomon bicolor from the Tyrrhenian coasts of Sicily, together with first data on its population density and biomass in the Gulf of Milazzo. Hard bottom samplings carried out facing the wastes of the local industrial pole, showed very high values of densities (421±294 specimens/400cm²) and biomasses (163±103 g) from 0 to 1.5 m of depth, demonstrating a high invasive potential. Evidence of a possible competition with the naturalized Lessepesian mussel Brachidontes pharaonis have been also reported.