Physiological and histological characterization of juvenile sockeye salmon in the first summer and fall of foraging in the ocean | Физиологическая и гистологическая характеристики молоди нерки в первое лето нагула в море

It has demonstrated on the base of the analysis of biological, biochemical and histological researches of juvenile sockeye salmon from the lake Kurilskoye in its' first summer and fall in the ocean for 2001-2005 that the rate of sexual maturation depends on duration of the 1 and 2 stages of gonad maturation. Duration of these stages depends onthe previtellogenesis of oocites. Temperature and food supply, dependently the abundance of foraging juveniles, which indicator is the abundance of parental generations of two adjacent years to spawn in the lake, are the principle ecological factors to determin the rates of the 1 and II stages of maturation. Quicker juvenile growth and pad development for the first months of foraging in the ocean is characteristic for low abundant generations of le Ozemaya River sockeye salmon, which growth and development determination has set during freshwater period under the term of mixed foraging by generations from two adjacent years (generation abundance 3,0 million fishes). Low rate of the oocite development during freshwater period also influences the rate of the development during the first months of foraging in the ocean. An increase in the body weight at a high juvenile sockeye salmon abundance indicates of favorable conditions for juvenile foraging in the ocean by sockeye salmon from West Kamchatka (Kurilskoye Lake) formed for the period 2001-2005. For the period analyzed an increase in the biological characteristics (body length and weight), relative content of fat in the muscle tissue offish, calorie content and food supply index has traced. Since minimal in 2001 the energy index was much higher next years. Tie biochemical indexes can rather indicate of the influence of the conditions of foraging on juvenile growth and hardly can strongly influence the gonad development for the first months of foraging in the ocean