Strong currents in the south-east monsoon period resulted in a few bags lying in the sand which was detrimental to spat settlement. imbricata radiata populations in the Saronikos area (Greece) have rather excluded shipping as the mode of transportation ( Zenetos et al., 2004b).Abstract Forty oyster spat collector bags were submerged at two different sites near Mahe island fofr a period between 3.2 and 11 months. Subsequent findings of this species in areas where aquaculture activities (historical or recent) are absent support a Lessepsian mode of introduction ( Zenetos et al., 2005). imbricata radiata was naturalised and expanded in the Hellenic Seas ( Pancucci-Papadopulou et al., 2005). In 1963 it was imported for aquaculture purposes to Greece, but its cultivation did not prove prosperous and was thus abandoned. It was subsequently reported from Tunisia (1890), Israel (1899), Cyprus (1899), and Malta (1912). It was collected on the shores of Alexandria, Egypt and was one of the very first marine species of Indo-Pacific origin to cross the Suez Canal into the Mediterranean. imbricata radiata was first reported outside its natural biogeographical distribution in 1874 in the Mediterranean Sea. On macro-litter one shell First reported: 2013-2014Īzores Islands Original citation: Àvila et al. Native on Red Sea coast, Introduction in Mediterranean coast The internal side has a highly iridescent nacreous area, whereas the non-nacreous margin is glossy and light brown in colour, usually with dark brown or reddish blotches corresponding to the main external rays ( Zenetos et al., 2004a). The outer surface has densely set, appressed and flattened imbricating concentric lamellae, and often moderately small radially projecting spines, mostly preserved towards the margins. Sometimes, green and bronze coloration has been observed. It can be uniform or with darker markings on radial rays, and is generally brownish or reddish. The external coloration of the shell is variable. The common size of this oyster is usually 50-65 mm. ![]() The ligament is set in a single triangular depression. The beaks point anteriorly, and the hinge line is straight with no teeth present. The posterior margin is slightly concave and protrudes only slightly (or not at all) beyond the tip of the anterior ear. The dorsal margin is relatively long, and definitely longer than the body of the shell. The shell is inequivalve with the left valve more inflated, and has an almost quadrate outline. imbricata radiata have a fragile, rather thin and compressed, small to medium size shell. imbricata radiata is currently not on any alert list, but it is listed among the worst alien species in the Streamlining European 2010 Biodiversity Indicators on invasive alien species ( European Environment Agency, 2007).Īdult P. It is now established in all places where it has been introduced and it is steadily expanding its range ( DAISIE, 2009). It was first recorded as invasive in Tunisia ( Vassel, 1896). It is considered to be a habitat-modifying and gregarious bivalve, capable of impacting native fauna by forming oyster banks ( DAISIE, 2009). ![]() It also has the ability to adapt to a changed environment ( Mohamed et al., 2006) and its tolerance to chemical contamination has enhanced its expansion in enclosed polluted ecosystems ( Katsanevakis et al., 2008). ![]() It is a relatively hardy species, tolerant to emersion (O’ Connor et al., 2003) and to a wide temperature range (13-30☌) ( DAISIE, 2009). imbricata radiata is considered to be one of the worst invasive species in the Mediterranean Sea, in terms of spread and impact. Pinctada vulgaris (Schumacher) Ĭeylon pearl oyster Persian Gulf pearl oysterĪccording to Streftaris and Zenetos (2006), P.Pinctada imbricata (Röding, 1798 Reeve, 1857 Jameson, 1901).Meleagrina conemenosi Monterosato, 1884.Pinctada imbricata radiata (Leach, 1814).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |