The biology of lenok <i>Brachymystax lenok </i>(Pallas) of the upper streams of the Lena River
The base biological parameters of lenok <i>Brachymystax lenok </i>(Pallas) of the upper stream of the Lena River were investigated, such as morphometric characters, age and size composition, growth, spawning period, fecundity and diet. No significant differences were found in values of morphometric characters. Some differences in the diet and growth rate were found.