Age changes in the relative weight of the liver Thymallus arcticus of the Kazyr river (r. Yenisey basin)

The article discusses the results of studies of the morphophysiological index of the liver of Thymallus arcticus, which was caught in the Kazyr River (Krasnoyarsk Territory) in the autumn period (end of October) 2020. The analysis of the liver index (morphophysiological indicator) is presented. Information on the change in the relative weight of the liver with age of Siberian grayling is also presented. The information and the location are new to research.