中华绒螯蟹卵巢快速发育期内脂类积累以及对抱卵的影响

The lipid accumulations during the stages of the ovarian fast maturation and their effect on the spawning of Eriocheir sinensis

本文报道中华绒螯蟹卵巢快速发育期内 (9月初至 12月初 )脂类积累及对抱卵的影响。结果表明 :在这一时期 ,卵巢重量和脂肪含量都迅速增加 ,增加的脂肪中 ,中性脂 (NL)主要是甘油三酯和胆固醇 ,磷脂 (PL)主要是卵磷脂和脑磷脂 ,且NL或PL在总脂的比值比较稳定 ;无论是NL还是PL , 3 系列的多不饱和脂肪酸 (主要是C2 0∶5和C2 2∶6)的百分组成都显著增加 ,而 6系列的 (主要是C2 0∶4 )百分组成则显著降低 ;不能够抱卵的成熟蟹卵巢脂类组成与正常成熟至抱卵的蟹相比 ,具有较低含量的磷脂 ,脂肪酸组成中 ,长链多不饱和脂肪酸相对百分含量 ,如c2 0∶5和C2 2∶6也较低。

The lipid accumulations during the stages of the ovarian fast maturation(from September to December) and their effect on the spawning of Eriocheir sinensis were studied.The results shown that gonadosomic index(GSI) and lipid content were significantly increased,both neutral lipids(PL)(mainly triacylglycerol and cholesterol) and phospholipid(PL)(mainly phosphatidylethanmine) were responsible for the increase in ovarian lipid,and NL increasing from 13.67% to 20.12% ovary dry weight,PL from 7.21% to 10.70% ovary dry weight.The ratio of NL/TL or of PL/TL remained relatively constant during the fast ovarian development,and NL concentration of ovary were always higher than that of PL.The fatty acid composition of lipids,PL and NL of ovaries varied markedly during this development stage.There was much more long-chain polyunsaturated fatty acids such as C 20∶5 and C 22∶6in the mature ovary than those at the start of fast development of immature ovary(NL P<0.05;PL P<0.01),but the percentage of C 20∶4 decreased significantly (P<0.01) during this stage.It was also found the mature crab that could not spawn was partly because of their lower PL content(%ovarian dry wt) and lower percentage of the C 20∶5 and C 22∶6 in PL than that of normal mature ovaries in Dec.The results suggest that the lipid, manily phospholipid and long-chain polyunsaturated fatty acids such as C 20∶5and C 22∶6 are essential for ovarian fast development and must be obtained from dietary source.