On the occurrence of Pinctada radiata (Mollusca: Bivalvia: Pteriidae), an alien species in Croatian waters

The family Pteriidae (Bivalvia: Pterioida), which includes the group of species known as “pearl oysters” comprises three genera, namely Pteria Scopoli, 1777, Pinctada röding, 1798 and electroma Stoliczka, 1871 (CLEMAM, 2008). This family is represented by three species (Pteria hirundo (Linné, 1758); Pinctada radiata (Leach, 1814) and electroma vexillum (Reeve, 1857)) in the Mediterranean according to CLEMAM, while ZENETOS et al., (2003, 2005) have included two more species, namely Pinctada margaritifera (Linné, 1758) and Pteria occa (Reeve, 1957). All of these species except P. hirundo are alien species that have been introduced to the Mediterranean either via the Suez Canal (P. radiata, P. occa), by aquaculture activities (P. margaritifera, P. radiata) or via shipping (e. vexillum) (GOfAS & ZENETOS, 2003; ZENETOS et al., 2003; ÇevIk et al., 2005). Pinctada radiata had been first recorded in 1874 as Meleagrina sp. from Egypt (MONTEROSATO DI, 1878) with the species seeming to have become well established in extent throughout the eastern Mediterranean (ZENETOS et al., 2003) including Sicily (DE NATALE, 1982). Accidental occurrences have been recorded in france (ZIBROWIUS, 1979) and Italy (VIO & DE MIN, 1996). New data for the locality of P. radiata in the Adriatic Sea are provided in this study in which the species is reported for the first time in Croatian waters.