Laboratory of Fish Physiology

HEAD Sergey L.KONDRASHEV, Cand. Sci. Biol.

STAFF numbers 11, including 1 Dr. Sci, 2 Cand. Sci.

RESEARCH OBJECTIVES: Study of the cellular processes of reproduction control and adaptation to environmental conditions in Pacific salmon; comparative physiological investigation of the visual system in marine animals.

It has been shown that after migration from the sea to fresh water during the spawning run, the systems of ionic and osmotic regulation of pink salmon preserve, with a high degree of stability, the main constants of the water-salt balance in the blood serum and internal fluids. During the spawning migration the large cells and small cells in the preoptic nuclei of the pink salmon hypothalamus show two periods of pronounced functional activity: one after passage from the sea to river and the other before spawning. The first activation period is connected with the change of habitat and intensification of sexual maturation and the second is connected with “spawning stress” and the completion of maturation. During starvation exogenous insulin activates enzymes of utilization of endogenous glucose in fish. It has been established that exogenous salmon gonadotropin considerably activates the gonad growth in immature young chum salmon.

In collaboration with the Institute of Especially Pure Biopreparations (St. Petersburg), prolactin has beeb, for the first time, isolated from pink salmon, purified and tested.

Special attention has been given to investigation of the visual system and visually guided behavior in fish. A new phenomenon in the physiology of fish visual analyzer, change of the eye cornea coloration in relation to light conditions, has been discovered and described. In comparative aspect, a scheme of the structure of nerve centers of the brain in arthropods has been developed and morphophysiological organization of the peripheral part of the visual system of decapod crustaceans from the Sea of Japan has been studied. A complex study is being conducted of the correlations between the fine morphology of fish retinal neurones and their functional properties.

Phone: 31-11-50