Honeyfield Dale C, Fitzsimons John D, Tillitt Donald E, Brown Scott B
U.S. Geological Survey, Northern Appalachian Research Laboratory, 176 Straight Run Road, Wellsboro, Pennsylvania 16901, USA.
J Aquat Anim Health. 2009 Dec;21(4):272-8. doi: 10.1577/H08-006.1.
We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.
我们之前证明，以两种密歇根湖被捕食鱼类（灰西鲱Alosa pseudoharengus和圆腹雅罗鱼Coregonus hoyi）为食的湖鳟Salvelinus namaycush的鱼卵硫胺素含量存在显著差异。以灰西鲱为食的湖鳟产出的鱼卵硫胺素含量较低，但尚不清楚食用灰西鲱是否会影响其他营养重要成分。在本研究中，我们调查了雌鱼食用导致不同鱼卵硫胺素浓度的日粮时湖鳟鱼卵的脂肪酸组成。连续两年，成年湖鳟被投喂由捕获的灰西鲱和圆腹雅罗鱼的四种组合构成的日粮（100%灰西鲱；65%灰西鲱，35%圆腹雅罗鱼；35%灰西鲱，65%圆腹雅罗鱼；以及100%圆腹雅罗鱼）。灰西鲱的脂肪酸谱中花生四烯酸和总ω-6脂肪酸的浓度高于圆腹雅罗鱼的脂肪酸谱。四种脂肪酸（顺式-13,16-二十二碳二烯酸、二十碳五烯酸、二十二碳五烯酸和二十二碳六烯酸）在圆腹雅罗鱼中的浓度高于灰西鲱。尽管2001年湖鳟鱼卵中的六种脂肪酸成分高于2000年，八种脂肪酸低于2000年，但在本研究中，日粮对湖鳟鱼卵中测量的任何脂肪酸浓度均无影响。基于这些结果，似乎鱼卵脂肪酸浓度在不同年份有所不同，但鱼卵脂肪酸谱并未反映成年湖鳟日粮中灰西鲱和圆腹雅罗鱼的混合比例。以灰西鲱和圆腹雅罗鱼为食的雌鱼所产湖鳟鱼卵的必需脂肪酸含量似乎受到生理调节，足以满足发育中胚胎的需求。
