About the survival of muksun embryos and larvae of the depending on the time of insemination of the eggs after collection

Abstract

The goal of the research was to study the viability of the offspring of the Coregonus muksun obtained from eggs inseminated at different time (-from 0 to 220 min) after collection.Classical fish breeding methods were used in the work: eggs was inseminated by dry method, incubation was carried out in sieves and modified Weiss devices with a volume of 1 l, juveniles were grown in 60 liter pools with a stocking density of 150 ind./pool, artificial diet and artemia nauplii served as food.Such studies in fish breeding practice are carried out for the first time, which determines their novelty.As a result of the research, an almost linear dependence of the survival rate of the offspring of muksun on the time of insemination of ovulated eggs was established with a very high degree of approximation reliability (R2) for embryos 0,906, larvae 0,846. The best survival rate of embryos and larvae was obtained in experimental variants in which eggs were inseminated in the first hour after collection. The proportion of live eggs at the end of incubation and larvae after 38 days of rearing was 57,5-58,9% and 78-84%, respectively. The survival rate of embryos and larvae in the experimental variants in which eggs were inseminated 80-100 minutes from the moment of collection were in the range of 40,1-42,2% and 49,4-50,1%, respectively; for 120-160 minutes 9,4-15,3% and 45,3-47,6%; for 180-220 min the survival rate of caviar did not exceed 5,0%, larvae- 45,6%.The practical significance of the work lies in determining the optimal period between the collection and insemination of eggs with the least risk to the viability of the offspring, which is of great importance in works on the artificial reproduction and cultivation of valuable fish species.