Since the mid 1980th members of the family Corbiculidae were found in central Europe in increasing numbers. This family is mainly distributed in the australasian region and is also found in Africa. The northwesternmost range is Anatolia, where Corbicula fluminalis (O. F. Müller 1774) occurs. In Europe there is supposed to exist recent populations in the Caucasus Mountains (Illies 1978). While nowadays this species is extinct in central Europe, it is regarded as a leading species sensu latu of the interglacial period 230,000 years ago (Schütt 1990). The population of Corbicula fluminalis in the Near East are stable if not declining (Kinzelbach 1992), while two east asian species have been introduced in central european rivers probably via North-America. The River Rhine probably has been colonized in 1989 (Bij De Vaate 1991).