The invasion of the alien crayfish Procambarus clarkii in Europe, with particular reference to Italy.

The red swampcrayfish, Procambarus clarkii native to the southcentral United States (Louisiana) and north-eastern Mexico, have been transplanted world-wide . This is a large, prolific, aggressive species, and it is well adapted to life in areas with drastic, seasonal fluctuations in water levels, where it survives by digging deep burrows. Since 1990, P. clarkii has been found in a number of ponds and streams of several provinces of northern and central Italy, where populations seem to increase rapidly, in contrast to the native species, Austropotamobius pallipes.