Crayfish with white legs

The crayfish with white feet or white legs is a species meeting only in the west of the Europe: Ireland, Great Britain, north and is Spain, north of the Portugal (where it was introduced into the years 1930), France (it was introduced in Corsica), Italy, Yugoslavia and in a more sporadic way in Germany, Suisse and Austria.

This species meets in the clear rivers everywhere in its surface of distribution as well as lakes and channels in Ireland and Great Britain. Its distribution depends on the temperature of water and the force of the current. The driven are in water with an higher temperature with 10 °C, the adults are visible from June to September, the activity is reduced in winter.

Its populations can be frays with that of Astacus crayfish in France and Germany. Astacus torrentium occupies of the different territories when the two species occupy the same rivers (in Germany, Austria, Switzerland and Yugoslavia).

Maturity is reached when the animals reach five centimetres length (at the age of two or three years). The reproduction claims water higher than 12 °C in October. The eggs, between 40 and 150, are incubated during six to nine months. The maximum size of the adults is from 9 to 12 cm, those weigh then from 30 to 90 G. The sizes and the weights maxima are reached when the animal has a dozen years.

Food is made up for the youngest crayfish by small Invertébré S, the adults consume as for them terrestrial or watery plants. The cannibalism of the adults on the young people maintains the level of the populations.

The threats weighing on this species are numerous: the crayfish of Louisiana introduced into its medium brought a disease, Aphanomycosis, which decimates the populations in Spain, Great Britain and undoubtedly Ireland. The pollution and the acidification of water are probably also a cause of the fall of manpower.

External bonds

Random links: