Quantitative genetic analysis indicate non-heritability of major fatty acid in the muscle of Chinese mitten crab (Eriocheir sinensis)

The Chinese mitten crab ( Eriocheir sinensis ) is a commercially important aquaculture species, and crab meat generally has the high percentage of long-chain polyunsaturated fatty acids (LC-PUFAs) in the total fatty acids, which contributes the unique flavor and high nutrition value for adult crab. Muscle is the largest edible tissue in crustaceans, containing a variety of fatty acids, and understanding the genetic parameters of fatty acids in the meat of E. sinensis would be useful for the aquaculture of this species. This study investigated the heritability, genetic and phenotypic correlations of major fatty acids in the muscle of E. sinensis . Progeny from 25 full-sib families were reared under a common environment until they reached market size, and 429 mature crabs were selected for analysis. The results showed that the heritabilities of most fatty acids were low ranged from 0.01 (n-3PUFA) to 0.21 (MUFA), but the high heritabilities were recorded for C20:3n3 and C20:3n6 with values of 0.99 and 0.32, respectively. Furthermore, the strongest positive genetic correlations were found between C20:5n3 and C22:6n3(0.99), n-3PUFA(0.99), and PUFA and LC- PUFAs (0.99), n-3PUFA(0.99), whereas the strongest phenotype correlation was found between C20:5n3 and n-3 PUFA (0.96); C20:3n6 showed a significant negative genetic correlation with C20:3n3(−0.86) and C18:0 (−0.98), whereas C20:3n6 showed significant negative phenotypic correlation with C20:3n3(−0.14), C20:5n3(−0.15) and C22:6n3(−0.18). In conclusion, the percentages of major fatty acids, particularly C20:5n3, C22: 5n3 and C20:4n6, in E. sinensis muscle have very low heritabilities, suggesting that these fatty acids contents/composition in the muscle are ineffective targets for the selective breeding programs of E. sinensis . • The percentage of major fatty acids were low heritable while C20:3n6 and C20:3n3 had the moderate and high heritability. • Significant negative genetic correlation (−0.86) and phenotypic correlation (−0.14) were found between C20:3n3 and C20:3n6. • Results indicated that genetic breeding may be ineffective to improve fatty acid composition in the muscle of E. sinensis .