Opilio crab (lat. Chionoecetes opilio) belongs to crustaceans; the fifth pair of limbs (which he hides under the abdomen) indicates its true origin. In Russia, it lives in the Barents and the Okhotsk seas at depths from 7 to 100 m, where the temperature of the bottom does not fall below 2 degrees Celsius. It eats molluscs, larvae, crustaceans.
The carapace diameter is from 2 to 16 cm, the weight is up to 2 kg, that is significantly less than the King crab or blue crab. It looks rather faded: brown, sometimes with a reddish tinge, gray limbs and white or yellow abdomen.
Mature individuals prefer deep shelf waters; little crabs, on the contrary, stick closer to the shore. Young crabs lives in schools, then they lead a separate lifestyle, but sometimes there are dense groups.
There are strict rules: catching female fledglings and individuals whose carapace is less than 10 cm is not accepted.
Due to the fact that crab meat is very nutritious and useful with many minerals this dietary product is valuable all over the world.