Arrived from SW. Pacific with the increase of shell-farming in southern Europa. Invasive, it lives in huge colonies in brackish waters and lagunar systems around Mediterranean: Venezia, Bocca del Po, Ravenna, Gulf of Olbia, Le Grau du Roi, Fulvià river mouth… This species is able to live « over a wide range of temperature and salinity conditions » (Astudillo, Bonebrake & Leung, 2017). — Original taxon: Modiola securis. Synonyms: confusa, fluviatilis, vexillum…
« Testâ oblongâ, incurvâ, infernè carinato-acutâ; epiderme fusco-nigricante; intus violaceâ. » – J.-B. P. A. de Lamarck: Hist. nat. des animaux sans vertèbres…, vol. VI, Paris 1819.