Influence of Temperature on the Sterlet (Acipenser ruthenus L.) Ovarian Follicles State

Abstract

We studied the effects of changes in the temperature of water in which the sterlet (Acipenser ruthenus L.) females were kept on morphometrical and physiological characteristics of the ovarian follicles: size of oocytes, their polarization index, and their capacity to mature and ovulate in vitro in the presence of progesterone or purified preparation of gonadotropic hormone of the sturgeon pituitary, as well as ‘spontaneously’ in the culture medium. When the temperature was lowered from 13°C, the optimal for spawning, to 6°C, the morphometrical parameters remained unchanged, but the indices of the physiological state underwent changes. After the temperature was gradually elevated to the initial value, some indices returned fully or partially to the initial state, while others continued to change in the same direction.