Austropotamobius pallipes fulcisianus
Italian white-clawed crayfish
92/43/EEC Directive ann. II and V
The Italian white-clawed crayfish attends the resurgences canals where the current is moderate or strong and where the bottom is mostly gravel and sand.
It is crepuscular and nocturnal habits, during the day live hidden among the roots of trees, under rocks or in tunnels dug along the banks. It is omnivorous and feeds on plants and invertebrates. It breeds from September to October. The females carry the fertilized eggs under the abdomen until early next summer when the larvae are born. They become mature after 3-5 years.
All crustaceans live in a kind of rigid armour that does not increase in size with the growth of the animal and is therefore changed when it becomes too narrow (moult).
When it happens, the crayfish needs to find an hiding place because it is very vulnerable to predation. The moult start with the split of the old back cover, after the crayfish comes out slowly; the crayfish just shelled is soft and its body covering hardens slowly. After few hours is quite rigid and crayfish can come out of hiding. The old covering is called exuviae and is released into the environment.
This species is present in all Italian regions, islands except. The fulcisianus subspecies is endemic of Italy.
The crayfish is considered to be in decline in Italy due to the deterioration of the biological quality of rivers (pollution) and the modification of natural watercourses.
Its decline is quicken by the abundant catch (banned for many years in Friuli Venezia Giulia), by the introduction of species of crayfishes from other countries and by the spread of a fungus that causes the "crayfish plague".
Recently it has been entered into regional waterways the Louisiana red crayfish (Procambarus clarkii), initially imported for food and ornamental aims, but characterized by a remarkable ability to displace native species through the competition for space and food both through the transmission of diseases. Its reproductive capacity and its high mobility creates concern for the conservation of freshwater crayfish and for the balance of the aquatic ecosystem maintenance.
A. Toselli ©