Haracteristic of the biology of the European flounder Platichthys flesus (Pleuronectidae) of the lower reaches of the Mezen river according to research data 2010–2016

The biological characteristics of the European flounder of the lower reaches of the Mezen River are described. The maximum age of 18 years was noted, the maximum zoological length and weight: 41,2 cm and 680 g. The size and weight characteristics of individuals for each age are given. The relationship between the length and mass of the river body is described by a power function. Single maturing individuals were caught at the age of 4 years in females and 3 years in males. The bulk of the fish ripens at 4–5 years of age. Food items are marked: amphipods, bivalve mollusks, insect larvae, including brooks, sipunculids, fish objects. The average absolute fecundity of European flounder is 550 thousand eggs.