Вестник МГТУ. 2018, том 21, № 2.

Ливадина Л. В. и др. Морфологическое развитие пищеварительной системы... L . V . Livadina, V . S. Anokhina Morpho log ica l development o f the digestive system o f A tlan tic salmon Salmo salar L . in the Umba fa rm du ring the endogenous feeding The morphological and histological characteristics of the digestive system ontogenesis in hatchery of the Atlantic salmon larvae during the endogenous feeding period have been given. An analysis of a number of articles updating information on modern studies of the digestive system in the early ontogeny of various groups o f fish has been carried out. The samples were collected at the Umba hatchery in 2015-2016. The authors have performed morphological and histological analyses o f embryos and larvae, histological examination o f the digestive system o f larvae during the transition to exogenous nutrition, the establishment o f biological age at the time o f certain events in the ontogenesis o f the digestive system. Actual values o f the biological age o f Umba hatchery larvae, at which they shift to the mixed (580 tau-somite) and exogenous (630 tau-somite) feeding have been determined. The obtained results have been compared with the literature data when development of Atlantic salmon larvae takes place in conditions with controlled temperature. Variation in biological age values, when formation o f the digestive system structures takes place, has pointed at the functional and morphological differences in ontogenesis o f the Atlantic salmon from natural and artificial water circumstances. Development o f the Atlantic salmon larvae after hatching in cold-water conditions (3 -4 ° С, the Umba hatchery), sequence of the digestive system structures composition, and establishment o f the functional readiness to food assimilation has been shown. In this period the growth rate o f larvae has been evaluated. The organs responsible for exogenous feeding have been divided into 3 groups, and analysis o f their ontogenesis has been performed. It has been recommended to start exogenous feeding with 15-20 % o f yolk in presence, at the biological age of 540 tau-somite, 45-48 days after hatching in our case. Key words: hatchery production, Atlantic salmon, early onthogenesis, endogenous feeding, Salmo salar , digestive system, histology, biological age. 294