Highly Unsaturated Fatty Acids: The Missing Link in Aquatic Food Webs?

9615888戈德曼在水生食物网中，通过植物-草食动物界面的能量流动是高度可变的，控制浮游植物转化为浮游动物生物量的效率的因素知之甚少。这项研究的目的是提高对调节能量转移效率、二次生产和营养级联强度的过程的理解。中心假设是，Seston中的高度不饱和脂肪酸(HUFA)含量强烈地影响着这些过程。HUFA的生物学意义在动物细胞膜生理学、激素合成、人类健康和营养以及水产养殖等领域是一个很有前途的快速发展的研究领域。HUFA之所以重要，主要有两个原因：第一，它们对动物细胞膜的流动性有很大的影响，是二十烷类化合物(包括前列腺素、狼尾藻三烯和其他动物激素)的前体；第二，它们只由植物产生。与许多脂质不同，HUFA不用于能量储存。这些事实导致了具体的预测：在Seston以高HUFA含量的浮游植物为主的时期，耦合将是紧密的，能量转移将是有效的，而在HUFA Seston低的时期，耦合将是弱的。在不同湖泊类型的比较中已经观察到了这种模式，在以HUFA贫乏的蓝藻为主的湖泊中，耦合很弱，在以富含HUFA的硅藻和隐芽植物为主的湖泊中，耦合很强。在这项研究中，将在一系列实验中测试对这些模式的控制，以检查Seston元素和生化组成与浮游动物生长和生长效率的关系。

9615888 Goldman In aquatic food webs, the flow of energy across the plant-herbivore interface is highly variable and the factors controlling the efficiency at which phytoplankton is converted to zooplankton biomass are poorly understood. The objective of this research is to improve understanding of processes that regulate efficiency of energy transfer, secondary production and strength of trophic cascades. The central hypothesis is that the highly unsaturated fatty acid (HUFA) content of seston strongly influences these processes. The biological significance of HUFA is a promising and rapidly developing area of research in a very wide variety of fields including animal cell membrane physiology, hormonal synthesis, human health and nutrition, and aquaculture. HUFA are important for two principal reasons: first, they have a large impact on animal cell membrane fluidity and are precursors for eicosanoids (which includes prostaglandins, luekotrienes and other animal hormones), and second, they are only produced by plants. Unlike many lipids, HUFA are not used for energy storage. These facts lead to the specific prediction that during periods when the seston is dominated by phytoplankton with high HUFA content, coupling will be tight and energy transfer will be efficient, while during periods with low-HUFA seston, coupling will be weak. This pattern has already been observed in comparisons among lake types, with very weak coupling in lakes dominated by HUFA-poor cyanobacteria and tight coupling in lakes dominated by HUFA-rich diatoms and cryptophytes. In this research, controls on these patterns will be tested in a series of experiments to examine the relationship between seston elemental and biochemical composition and zooplankton growth and growth efficiency.