Shields R J, Bell J G, Luizi F S, Gara B, Bromage N R, Sargent J R
Sea Fish Aquaculture, Ardtoe, Argyll PH36 4LD, Scotland, U.K. and Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, U.K.
J Nutr. 1999 Jun;129(6):1186-94. doi: 10.1093/jn/129.6.1186.
Replicate groups of halibut larvae were fed to d 71 post-first feeding (PFF) either the marine copepod, Eurytemora velox, or Artemia nauplii doubly enriched with the marine chromist or golden algae, Schizochytrium sp., (Algamac 2000) and a commercial oil emulsion (SuperSelco). The fatty acid compositions of eyes, brains and livers from larvae fed the two diets were measured, and indices of growth, eye migration and skin pigmentation were recorded along with histological examinations of eye and liver. The docosahexaenoic acid [22:6(n-3); DHA]/eicosapentaenoic acid [20:5(n-3); EPA] ratios in Artemia nauplii enriched with the SuperSelco and Algamac 2000 were 0.4 and 1.0, respectively. The E. velox copepods were divided into two size ranges (125-250 and 250-400 microm) with the smaller size range containing the highest level of (n-3) highly unsaturated fatty acids (HUFA). The DHA/EPA ratios for the two size ranges of copepods were 2.0 and 0.9, respectively. The total lipids of eyes, brains and livers of larvae fed copepods had higher levels of DHA and lower levels of EPA than those of larvae fed enriched Artemia. The percentage of survival of the halibut larvae was significantly higher when copepods rather than enriched Artemia nauplii were fed, but larval specific growth rates did not differ. The indices of eye migration were high and not significantly different in larvae fed the two diets, but the percentage of larvae undergoing successful metamorphosis (complete eye migration and dorsal pigmentation) was higher in larvae fed copepods (40%) than in larvae fed enriched Artemia (4%). The rod/cone ratios in histological sections of the retina were 2.5 +/- 0.7 in larvae fed copepods and 1.3 +/- 0.6 in larvae fed enriched Artemia (P < 0.01). Histological examination of the livers and intestines of the larvae were consistent with better assimilation of lipid from copepods than lipid from Artemia nauplii up to 46 d post-first feeding. Thus, marine copepods are superior to enriched Artemia as food for halibut larvae in terms of survival, eye development and pigmentation, and this superiority can be related to the level of DHA in the feed.
将大比目鱼幼体的重复组在初次摄食后71天（PFF）分别投喂海洋桡足类动物——迅足猛水蚤（Eurytemora velox），或用海洋色素界生物或金色藻——裂殖壶菌（Schizochytrium sp.）（Algamac 2000）和商业油乳剂（SuperSelco）双重强化的卤虫无节幼体。测定了投喂两种饲料的幼体眼睛、大脑和肝脏的脂肪酸组成，并记录了生长、眼睛迁移和皮肤色素沉着指标，同时对眼睛和肝脏进行了组织学检查。用SuperSelco和Algamac 2000强化的卤虫无节幼体中二十二碳六烯酸[22:6(n-3)；DHA]/二十碳五烯酸[20:5(n-3)；EPA]的比例分别为0.4和1.0。迅足猛水蚤被分为两个大小范围（125 - 250微米和250 - 400微米），较小的大小范围内含有最高水平的(n-3)高不饱和脂肪酸（HUFA）。两个大小范围的桡足类动物的DHA/EPA比例分别为2.0和0.9。投喂桡足类动物的幼体眼睛、大脑和肝脏的总脂质中DHA水平较高，EPA水平较低，相比之下，投喂强化卤虫的幼体则相反。投喂桡足类动物时，大比目鱼幼体的存活率显著高于投喂强化卤虫无节幼体时，但幼体的特定生长率没有差异。两种饲料喂养的幼体眼睛迁移指标都很高且无显著差异，但投喂桡足类动物的幼体成功变态（完全眼睛迁移和背部色素沉着）的比例（40%）高于投喂强化卤虫的幼体（4%）。投喂桡足类动物的幼体视网膜组织切片中的杆状细胞/锥状细胞比例为2.5±0.7，投喂强化卤虫的幼体为1.3±0.6（P<0.01）。对幼体肝脏和肠道的组织学检查表明，在初次摄食后46天内，幼体对桡足类动物脂质的同化作用优于卤虫无节幼体脂质。因此，就存活率、眼睛发育和色素沉着而言，海洋桡足类动物作为大比目鱼幼体的食物优于强化卤虫，这种优势可能与饲料中DHA的水平有关。
