How to find a stone crayfish Austropotamobius torrentium (Schrank, 1803): A biogeographic study in Europe

The stone crayfish Austropotamobius torrentium (Schrank, 1803) is widely distributed in Southeastern and Central Europe. However, this information has not been verified until recently because of: ? ignorance about biogeographic notion and hydrography and ? ignorance of data in the literature. Overcoming these problems during the last decade, the distribution pattern of the stone crayfish has now become apparent in Europe. It is known from Luxembourg and Germany to the west, from Turkey to the east, from Germany and the Czech Republic to the north and from Greece to the south. It is absent in the northeastern part of the Pannonian basin as well as in Poland and Ukraine. Its presence in Luxembourg and the Czech Republic may be related not to natural distribution but to introduction by humans through history. The discovery of the stone crayfish in Italy and Turkey as well as its re-discovery in France during the 1990s proves the biogeographic conception that this animal belongs to the Danubian fauna. It probably originates from the southwestern part of the Pannonian basin.