The catfish (Silurus glanis) is a species of large predatory fish in the Siluridae family. It is widespread especially in Central and Eastern Europe, but also in Western Asia and can be found in Afghanistan or Kazakhstan. The catfish often live in ponds, lakes, on the lower course of larger rivers, as well as at their mouths in the Baltic Sea, Black Sea, Caspian Sea. Fish prefer deep places with mud and murky waters.
Sleep has a long body, with a flattened dorso-ventral head; it has a wide mouth, which has two long mustaches on the sides, short mustaches under the mouth. The body ends without a proper tail fin. On average, the cat has a length of 2 m, but can reach a length of 3 m and a weight of 150 kg. The body color is blackish bluish or olive green on the back, and the abdomen is a lighter color.
The spawning period is in the temperate regions between May and June, when the water has a temperature between 17 - 18 ° C. The eggs are deposited in places rich in aquatic plants. The amount of eggs laid depends on the feeding possibilities and the size of the female. At 2-3 days the seedling appears, which has a size of 4-5 mm. In the first 10 days they are sensitive to light. After this period they begin to move actively consuming plankton, small crustaceans. In case there is not enough food, cannibalism occurs. At the age of 4-5 years, sleep is suitable for reproduction.