Growth and commercial size of the Silver crucian carp Carassius gibelio, (Cyprinidae) Amur river

Abstract

This paper informs about characteristic of linear and weight growth of Amur silver crucian carp on the basis of the L. von Bertalanffy and I. I. Schmalhausen’s growth equations. For this description, the material collected in the period from 1997 to 2022 on the territory of two districts of the Amur River – in the watercourses of the Sredneamurskaya floodplain system and in the lower part of the Lower Amur was used. The main characteristics of the growth of the silver crucian carp is sexual dimorphism and compensatory growth. The maximum observed body length (Ad) of the Amur River silver crucian carp is 40 cm, body weight 2,1 kg. Differences were found in the indicators of linear, weight growth and growth rate of silver crucian carp living in the watercourses of the Middle Amur Lowland and in the lower part of the Lower Amur. Based on the coefficients of the growth equations, the coefficients of natural mortality for each year of life of females and males of silver crucian carp are calculated. The age of sexual maturity of females is 6 years. The commercial length of female silver crucian carp of the Middle Amur lowland, consistent with the age of mass maturation and the maximum biomass of generations should be equal to 20 cm, in the lower part of the Lower Amur – 23 cm.