饲料中大豆磷脂对红螯光壳螯虾性腺发育期营养物质积累的影响

基础饲料中添加5种不同水平的大豆磷脂(SL):0%(Diet 1),1%(Diet 2),2%(Diet 3),4%(Diet 4)和6%(Diet 5)。饲喂初始体质量为(25.64±1.53)g的红螯光壳螯虾(Cherax quadricarinatus)雌虾8周,观察其卵巢发育期个体生长、性腺指数等参数的变化,分析卵巢和肝胰腺营养物质积累的快慢以及与营养物质积累相关基因脂肪酸结合蛋白(FABP)mRNA表达的差异。结果表明:饲料中不同水平的SL对卵巢发育期红螯光壳螯虾的成活率和相对增重率(WG)影响不显著(P>0.05),但饲喂≥2%(SL)饲料的雌虾性腺指数(GSI)显著升高(P<0.05),雌虾的肝胰腺指数(HSI)则随饲料中SL的增加而呈下降趋势(P>0.05);随着饲料中SL的增加,虾肝胰腺中脂滴的体积增大,数量增多,结构更加完整,质地更加均匀,卵巢中脂滴和卵黄颗粒的数量增多,体积增大;同时,饲料中SL的增加促进了FABP在肝胰腺和卵巢中的表达量。综上所述,饲料中的SL对红螯光壳螯虾雌虾卵巢发育具有促进作用,在培育红螯光壳螯虾雌虾亲体过程中,含6.5%鱼油的基础饲料至少补充2%的SL有利于雌虾卵巢的快速发育。本研究旨在为深入研究虾蟹生殖生理学和规模化红螯光壳螯虾早繁苗种生产等提供基础资料。

Effects of dietary soybean lecithin on nutrient accumulation during gonadal development in the female Cherax quadricarinatus

The effects of increasing levels of dietary soybean lecithin (SL)on growth, ovarian development, tissue ultrastructure and fatty acid-binding proteins (FABP) mRNA expression(initial body weight 25.64 g±1.53 g), was investigated over 8 weeks. Five treatments were applied as 0% (Diet 1), 1% (Diet 2), 2% (Diet 3), 4% (Diet 4)2% SL had a significantly higher gonadosomatic index (GSI) than those fed with Diets 1 and 2 , and the hepatosomatic index (HSI) showed a decreasing trend with increasing levels of dietary SL>0.05). With increasing percentages of dietary SL, the hepatopancreatic lipid droplets increased in number and size and the structure and texture was more complete and evenly distributed. The ovarian lipid droplets and yolk granules also increased in number and size. Higher dietary SL yielded higher hepatopancreatic and ovarian FABP mRNA expression. Our results suggest that dietary SL has a positive effect on ovarian development in redclaw crayfishbroodstock, and at least 2% SL should be supplemented in broodstock diets to enhance ovarian maturation during aquaculture.