Stone crayfish

austropotamobius torrentium

The stone crayfish (Austropotamobius torrentium) is a crayfish from the group of decapods who resides faster forest and also mountain streams and is usually hidden in holes under rocks. It grows up to 10 cm in length. The body is usually brown. Underside of scissors is bright, usually brownish coloured and never red. The juvenile crayfish feeds on aquatic invertebrates, while adults feed on different plant material. Crayfish are food of other animals; adults are eaten by otter and water birds, young crayfish are eaten by fish.

Like most crayfish, this species also has external fertilization. The male defer his spermatophore on the chest part of the female armor. After that female hatches eggs, which are fertilized. The ovigerous females carried external eggs from early November until mid-June the following year. The new born crayfish stay in the shelter of the mother's tail up to 3 weeks. Small crayfish are several times molting before they reach full size. They can live 8 years.

navadni koščak (Austropotamobius torrentium)

Threats

In Slovenia the stone crayfish is listed on the Red list as vulnerable species. This species is most threatened by the presence of non-native species such as the Signal Crayfish (Pacifastacus leniusculus), the crayfish plague (Aphanomyces astaci), and habitat loss and degradation.

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