The indigenous crayfish Austropotamobius pallipes complex in a national park in Central Italy

The indigenous crayfish Austropotamobius pallipes complex has been recently defined by IUCN as an endangered species but our knowledge about its status in Italy is still provisional. An assessment of the most suitable environments for its survival is crucial to preserve the species and to develop appropriate conservation protocols for its management. To this end, during 2008 and 2009, we analyzed eight watercourses in a protected area of Central Italy for A. pallipes’ presence and for a number of environmental characteristics. Crayfish were found in four out of the eight analyzed watercourses: only one of three old reports was confirmed, while the species has disappeared from the other two. All the streams are characterized by good quality of both water and soil. The differences found for basin and riparian descriptors, canopy cover, shelters and substrate composition were independent of the crayfish presence. Non-indigenous crayfish populations were not recorded in the study area. Among the several causes of crayfish disappearance, overexploitation through illegal fishing, introduction of fish predators and drought seem to be the more likely. These threats should be urgently faced to guarantee the survival of the indigenous crayfish.