The European crayfish has a robust body, olive-brown to dark brown carapace on the dorsal side and lighter abdomen, with two powerful claws adapted for catching and manipulating food. The hard exoskeleton is periodically molted to allow growth; adult specimens can exceed 10 cm, with males often reaching up to 16 cm and females up to 12 cm.
Habits
Lives solitarily, nocturnal, hiding during the day under rocks or in burrows dug into river and lake banks; moves along the water bottom searching for food, digging in mud or sand to find invertebrates and organic debris.
Reproduction
Mating occurs in autumn; females lay hundreds of eggs attached to their abdomen and carry them on their pleopods throughout winter, with hatching occurring in spring or summer, and the young becoming independent after several weeks.
Distribution
Native to clean rivers and lakes in Europe (from France to Scandinavia and Russia), introduced to the United Kingdom, Morocco, and other areas; prefers well-oxygenated waters with rocky or clay substrate, often with submerged vegetation
