Distribution of crayfish in Italy
The distribution range of indigenous crayfish species in Italy has drastically decreased, mainly due to habitat destruction and poor water management. Specifically, this phenomenon has interested the white-clawed crayfish Austropotamobius pallipes complex, along with A. torrentium and Astacus astacus, now living in small and highly fragmented populations. On the contrary, alien crayfish species are quickly expanding their range, particularly the North-American Procambarus clarkii, Orconectes limosus, and Pacifastacus leniusculus. Conversely, Astacus leptodactylus, indigenous to the Ponto-Caspian basin, shows a confined distribution across Italy, possibly because it is susceptible to the crayfish plague. Actions for the conservation of indigenous crayfish require the integration of the knowledge acquired so far in Europe and elsewhere regarding conservation biology and resource management, but also effective means to disseminate information and develop and enforce legislation. It seems also crucial to underpin their value as heritage species through the education of the general public as a prerequisite of the success of any conservation initiative.