不同链长脂肪酸对斑马鱼的性腺脂肪酸组成、繁殖力与仔鱼成活率的影响

将体质健壮的4月龄斑马鱼(Danio rerio)亲鱼雄鱼(0.36±0.05) g/尾, 雌鱼(0.59±0.06) g/尾]雌雄各180尾, 随机平均分配在室内斑马鱼循环系统的18个养殖缸中。在斑马鱼基础饲料(对照组)中分别添加7 g/kg n-3HUFA (高不饱和脂肪酸, Highly unsaturated fatty acid)(HUFA组)及10 g/kg MCFA (中链脂肪酸, Medium chain fatty acid)(MCFA组), 制成3组等氮等脂饲料, 饲养90d后, 探究不同链长脂肪酸对斑马鱼的性腺脂肪酸组成、繁殖力和仔鱼成活率的影响。结果表明: (1)3组雌鱼性腺的脂肪酸组成均受到所饲喂饲料脂肪酸组成的影响, 其相关系数均在0.8以上。HUFA组雌鱼性腺中EPA和DHA的相对含量显著高于MCFA组及对照组(P<0.05), 而MCFA组与对照组之间无显著差异; HUFA组油酸的相对含量显著低于MCFA组及对照组(P<0.05), 而MCFA组与对照组之间无显著差异; HUFA组及MCFA组亚麻酸的相对含量与对照组之间均无显著差异, 但MCFA组显著高于HUFA组(P<0.05)。(2)HUFA组及MCFA组雌鱼的成熟系数、绝对繁殖力、体重与体长的相对繁殖力均显著高于对照组(P<0.05), 同时在雌鱼绝对繁殖力、相对繁殖力上, HUFA组显著高于MCFA组(P<0.05)。(3)将对照组雄鱼与各组雌鱼配对繁殖的结果显示, 分别与HUFA组及MCFA组雌鱼配对繁殖后的雌鱼的绝对产卵量、相对产卵量和仔鱼成活率均显著高于与对照组雌鱼的配对, 同时以上指标HUFA组雌鱼均显著高于MCFA组雌鱼(P<0.05)。将对照组雌鱼与各组雄鱼配对繁殖的结果表明, 与HUFA组雄鱼配对后其受精率均显著高于与MCFA组及对照组雄鱼的配对(P<0.05)。综上所述, 试验饲料显著影响斑马鱼雌鱼性腺的脂肪酸组成, HUFA及MCFA均可以促进斑马鱼雌鱼的繁殖性能和仔鱼成活率的提高, 在试验条件下, HUFA的效果更好。

INFLUENCE OF FATTY ACIDS WITH DIFFERENT CHAIN LENGTH ON FATTY ACID COMPOSITION OF OVARIES,FECUNDITY AND SURVIVAL RATE OF LARVAE IN ZEBRAFISH (DANIO RERIO)

To study the effects of fatty acids on zebrafish (Danio rerio), three diets with isonitrogenous and isolipidic nutrients of basal diet (control group), 7 g/kg n-3HUFA (Highly unsaturated fatty acid) (HUFA group) and 10 g/kg MCFA (Medium chain fatty acid) (MCFA group) were formulated to fed a total of 360 healthy four months old parent zebrafish including 180 male (0.59±0.06) g and 180 female (0.36±0.05) g fish that were randomly divided into three groups (triplicate per group) for a 90 days trial. The fatty acid composition of gonad, fecundity and larvae survival rate were used to assess the effects of fatty acids. The results indicated dietary fatty acids were effectively incorporated into ovaries of female fish with high coefficients that were all more than 0.8. EPA and DHA content in ovary tissue of HUFA group were higher than those in MCFA group and control group (P<0.05), and there was no significant diffe-rence between MCFA group and control group. Oleic acid was significantly lower in HUFA group than that of MCFA and control groups (P<0.05), and there was no significant difference between MCFA group and control group. Linole-nic acid content in HUFA group was higher than that in MCFA group (P<0.05), and linolenic acid content in the two groups were higher than that of control group. Gonadosomatic index, absolute fecundity, relative fecundity of weight and body length in HUFA group and MCFA group were significantly higher than those of control group (P<0.05) and the fecundity in HUFA group was significantly higher than that in MCFA group (P<0.05). For the mating experiment using female fish fed with different diet, absolute egg production, relative egg production rate of female fish and survi-val rate of larvae in HUFA group were significantly higher than that of MCFA group, and these two groups were signi-ficantly higher than control group (P<0.05). For the mating experiment using male fish fed with different diets, fertility rate in HUFA group was significantly higher than that in MCFA and control groups (P<0.05). The present result showed that the fatty acid composition in diets regulated fatty acids composition in ovaries of female fish, the reproduc-tion performance of female fish and the survival ratio of the larvae with the better beneficial effects for HUFA com-pared with MCFA.