ECOLOGICAL AND BIOLOGICAL CHARACTERISTICS OF THE SIBERIAN STURGEON (ACIPENSER BAERI BRANDT, 1869) IN LAKE BAIKAL // Nature of Inner Asia. - 2025. №1(30). . - С. 6-19.

ECOLOGICAL AND BIOLOGICAL CHARACTERISTICS OF THE SIBERIAN STURGEON (ACIPENSER BAERI BRANDT, 1869) IN LAKE BAIKAL

DOI: 10.18101/2542-0623-2025-1-6-19 UDK: 597.423

Sturgeons are a unique group of ancient fish, as well as valuable commercial species, predatory fishing of which has led to a catastrophic reduction in numbers throughout their range. The research is aimed at studying the distribution, growth and feeding characteristics of the Siberian sturgeon (Acipenser baeri Brandt, 1869), a rare endangered species in the Selenga River and Lake Baikal. It has shown that in summer the distribution of the Baikal sturgeon in these waterbodies is determined by the features of the bottom landscapes. The spawning grounds of brood fish are located along the entire length of the Selenga River — from the mouth to its upper sections. Upon reaching breeding age, the growth in length of the Baikal sturgeon gradually slows down, and the body weight continues to increase. We havn't found a reliable differences in length and body weight of male and female individuals of the same age group of sturgeon. However, there is a direct correlation of the absolute fecundity of females with their age (r=0,71, p=0,05) and body weight (r=0,83, p=0,05). Relative fecundity decreases as the linear weight indicators increases, as well as the fatness of the females. It is noted that the Baikal sturgeon demonstrates selectivity in feeding, which is directly related to its habitat and season. During the feeding period in the Selenga shallow waters, the Proval Bay and the Selenga River delta its diet is dominated by amphipods and chironomids, during fattening in the river it is dominated by larvae of amphibiotic insects and young fish. Based on the stomach fullness indices, we have concluded that there is an abundant food supply in the Selenga shallow waters and its delta.

Acipenser baeri, Baikal population, Lake Baikal, distribution, linear-weight growth, fecundity, nutrition.