Comparative analysis of the variability of lipid total content in the skeletal muscles of the Baltic herring in the September 2017 and March 2018
The total lipid content (fat content) in skeletal muscles of spring-spawning Baltic herring, caught in September 2017 and March 2018, was determined. It was established that in September herring, with stage III maturity, the average lipid content (7.9%) is slightly higher (p <0.05) than with stage VI-II maturity (7.2%). The values of the coefficients of individual variability of fat content of skeletal muscles of the September herring catch (26.1%, 31.8%, 30.2% respectively for stages III, VI-II and without taking into account the stage of maturity) did not exceed the critical value of 33%, statistics to determine a homogeneous population, which indicates a certain com monality of the conditions of existence, behavior and nature of the exchange of fish of the September catch. When comparing two groups of March herring specimens of the same stages of maturity, no statistically significant differences were found between the total lipid content (2.3 and 2.4%, respectively, for stages III and VI-II) (p> 0.05), provided that the value of the coefficient of variation (87.5%, 69.5%, 71.3%, respectively, for stages III, VI-II and without taking into account the stage of maturity) significantly exceeded the critical value of homogeneity. The authors suggest that, at least in the post-wintering period, when the bulk of Baltic herring is represented by individuals with maturity stage III, gonad maturation processes are not associated with the expenditure of spare muscle lipids or activation of their accumulation, but can be provided by a small amount entering the body food.