Lipid Nutrition And Regulation Of Reproduction Of Chinese Mitten-handed Crab, Eriocheir Sinensis, Female

In crustaceans, it is well known that lipid is a kind of indispensable nutrient because of its important physiological function on cell, tissue, body structure and supplying energy to growth, development and reproduction. Lipid and fatty acids of broodstock diet have been identified as major dietary factors that determine successful reproduction, quality of offspring, and improve fatty acid profiles of hepatopancreas and egg. At the same time, some studies on crustacean endocrine had shown the Crustacean molting and reproduction regulated by steroids hormone. Up to date there are no reports on dietary lipid sources and contents influence on reproduction performance by endocrine regulation or other methods and how to regulate this process during the ovarian maturation.The Chinese mitten-handed crab, Eriocheir sinensis, is considered to be one of the most important species for commercial production in China. Lots of studies on Chinese mitten-handed crab has been conducted, however, Studies on nutrition of Chinese-mitten crab Broodstock is still few. From former studies on lipid nutrition of Chinese-mitten crab Broodstock reviewing, lipid nutrition has special effect on ovarian maturation of the Chinese mitten-handed crab, which, especially n-3 HUFAs, significantly affects reproduction performance of the Chinese mitten-handed crab, female broodstock, improves quality of offspring, optimize fatty acid profile of hepatopancancreas and egg. Moreover, dietary HUFAs and vitamin E, C are indispensable and cooperative to egg developing of crab and must be supplemented in the broodstock crab diet.It is still a secret how reproduction is affected by lipid nutrition. So in this paper, The main aim is to further probe into the mechanism how lipid nutrient affects ovarian development and reproduction performance, and regulation metabolism of lipid. To accumulate basal information for reproductive lipid nutrition, and provide reference for breeding broodstock in seed production and formulation of broodstock diet. In addition, effects of a-tocopherol and β -carotene, highly unsaturated fatty acids, in broodstock diet on reproduction performance, non-specific immunity and biochemical profiles of Chinese mitten-handed crab, are studied on basis of former research finding.1. Effect of dietary lipid sources and contents on ovarian development and reproduction performance on female Eriocheir sinensis, broodstockA 6 month feeding and reproduction trial was studied to investigate the effect of feeding eight kinds of compound diets containing different lipid sources and contents (6% fish oil, 6% peanut oil, 6% pork lard, 6% lecithin,0%,15% fish oil,15%porklard,15%lecithin) and fresh frozen-fish as the control diet on reproduction performance of Chinese mitten-handed crab broodstock. Broodstock crab fed the diet containing pork lard and peanut oil showed poor fecundity, low hatchability. Fecundity and hatchability of female crab fed 6% pork lard were only 56.9%, 32.57% of that fed 6% fish oil respectively. Broodstock fed the diets containing Alaska fish oil showed the highest fecundity, 2.787x103 cell/g. However, egg hatchability showed no significance between diet fed containing 6% lecithin and control group.During ovarian maturation, Hepatopancreas somatic index (HSI) is continuously decreasing, while Gonad somatic index (GSI) increasing in control group, especial during â…¢₁^â…¢₂ stage). In contrast to control group, the trend of nutrients transferring from hepatopancreas and storage to ovary in the group fed with diets lagged ,most sharp peak in â…¢₂^â…£ stage, which is more evident in groups fed diet containing Pork lard and peanut oil, especially Pork lard, which increased Vg content in hemolymph so as to nutrients sufficient storage in ovary at â…¢₁ stage. However, at â…£ ovarian mature stage GSI of female crab was 11.50 for lecitin,11.25 for fish oil, 8.85 for peanut oil and 7.30 for pork lard.Further studies of dietary lipid contents (0%, 15% fish oil, 15% pork lard, 15% lecithin) on reproduction performance of Chinese mitten-handed cra...