不同强化剂及其剂量对褶皱臂尾轮虫成活率和脂肪酸组成的影响

The effects of different enrichments and dosages on survival rate and fatty acid composition of Brachionus plicatilis

以小新月菱形藻强化效果为对照，研究了3种油脂型强化剂（墨鱼油、精制鱼油、混合鱼油）在不同剂量（0．25g／L、0．35g／L和0．45g／L）下强化12h后褶皱臂尾轮虫的脂肪酸组成和成活率。结果表明，不同强化剂和强化剂量下褶皱臂尾轮虫的成活率存在显著差异。用小新月菱形藻强化轮虫的成活率最高（96．82％），随着油脂型强化剂剂量的增大，轮虫的成活率显著下降。当强化剂量为0．45g／L时，墨鱼油型强化剂强化过程中轮虫的成活率仅为72．54％。不同强化剂强化后轮虫的脂肪酸组成有显著差异，强化前轮虫的EPA、ARA和DHA的量分别为2．56％、0．95％和7．73％，PUFA含量仅为16．65％。小新月菱形藻强化轮虫的EPA、ARA和DHA的量分别为12．27％、1．80％和8．61％，PUFA含量为26．00％。墨鱼油型强化剂强化的轮虫EPA、ARA和DHA的量分别为12．73％～13．47％、1．41％～1．46％和17．04％～17．96％，PUFA含量为39．36％～40．82％。精制油型强化剂强化的轮虫EPA、ARA和DHA的量分别为14．58％～17．00％、1．48％～2．78％和30．24％～31．93％，PUFA含量为55．53％～59．32％。混合鱼油型强化剂强化的轮虫EPA、ARA和DHA的量分别为13．34％～14．13％、1．38％～1．42％和24．88％～26．60％，PUFA含量为48．87％～50．70％。综合考虑轮虫成活率及脂肪酸组成，采用0．35g／L精制鱼油或0．25g／L混合鱼油强化银鲳仔鱼的饵料轮虫是合适的。

The fatty acid composition and survival rate of Brachionus plicatilis enriched respectively with 3 kinds of oil-enrichment （cuttlefish oil, refined fish oil, mixed fish oil） and microalgae Nitzschia closterium as control were studied. The effect of each kind of enrichment were assayed at different dosages （0.25 g/L,0.35 g/L and 0.45 g/L） after a 12h enrichment. The results showed that there were significant differences on survival among different enrichments and dosages. The survival rate of rotifers enriched with Nitzschia closterium was the highest （96.82%） , and the larger dosage of the oil enrichment, the lower survival rate of rotifer. The lowest survival was only 72.54% when 0.45 g/L cuttlefish oil enrichment was applied. The fatty acid compositions of rotifers were also changed significantly as different enrichment fed. The contents of EPA, ARA,DHA and PUFA of the rotifer without being enriched were 2.56%, 0.95%, 7.73% , and 16.65% respectively. The contents of EPA, ARA, DHA and PUFA in the rotifer enriched with Nitzschia closterium were 12.27%, 1.80%, 8.61% and 26.00% respectively. The contents of EPA, ARA,DHA and PUFA in the rotifer enriched with cuttlefish oil were 12.73% - 13.47%, 1.41% - 1.46%, 17.04% - 17.96% and 39.36% -40.82% respectively. The contents of EPA, ARA, DHA and PUFA in the rotifer enriched with refined fish oil were 14.58% - 17.00%, 1.48% - 2.78%, 30.24% - 31.93 and 55.53% - 59.32% respectively. The contents of EPA, ARA, DHA and PUFA in the rotifer enriched with mixed fish oil were 13.34% -14.13%, 1.38% -1.42%, 24.88% -26.60% and 48.87% -50.70% respectively. It is therefore suggested that rotifer enriched with 0.35 g/L refined fish oil or 0.25 g/L mixed fish oil for silver pomfret larvae should be suitable from the viewpoint of rotifer survival and fatty acid profiles.