Combined lipid, fatty acid and digestive tract content analyses: a penetrating approach to estimate feeding modes of Antarctic amphipods
Combined lipid, fatty acid and digestive tract content analyses: a penetrating approach to estimate feeding modes of Antarctic amphipods
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脂质、脂肪酸和消化道含量的综合分析：一种估算南极片脚类摄食模式的深入方法
作者：
M. Graeve;P. Dauby;Y. Scailteur
抽象的。研究人员收集了来自威德尔海和布兰斯菲尔德海峡的南极片脚类动物，以研究不同物种和摄食类型对脂质和脂肪酸组成的影响。结合消化道内容物分析，这些信息可以帮助阐明各种片脚类动物的摄食模式类型。微型和大型捕食性片脚类物种仅含有少量的三酰基甘油作为储存脂质，而沉积物饲养者Epimeria georgiana则富含三酰基甘油（占总脂质的55%）。脂肪酸22:6(n-3)、20:5(n-3)、18:1(n-9)和16:0是大多数物种的主要脂质成分。 Ampelisca richardsoni 是一种悬浮饲养动物，具有大量的 18:4(n-3)，它是隐植物和/或固定植物的主要成分，与以沉积的浮游植物物质为食并具有强烈的底栖-中上层耦合有关。在 Oradarea edentata 中，几乎只发现了褐藻碎片。大型藻类的主要脂肪酸 20:4(n-6) 取代了片足类磷脂和三酰甘油中的 22:6(n-3)。食海绵动物 Echiniphimedia hodgsoni 富含 16:1(n-7) 和 18:1(n-7)，表明无法识别的有机物源自硅藻。 Eusirus perdentatus 是一种典型的捕食者，具有高比例的饱和和单不饱和脂肪酸，在脂质和脂肪酸组成方面没有表现出特殊性。 Epimeria georgiana 的脂肪酸组成与 Eusirus perdentatus 相似。然而，乔治亚州艾美耳球虫中三酰甘油的高含量反映了周期性的食物充足和饥饿，因为它依赖于死物。坏死噬菌体 Waldeckia obesa 的脂肪酸组成明显不同，因为 18:1(n-9) 占主导地位（> 总脂肪酸的 40%）。这种优势可能是由于以高度降解的腐肉有机物为食的结果，而有机物是 W. obesa 的主要食物。
Abstract. Antarctic amphipods from the Weddell Sea and Bransfield Strait were collected to investigate the impact of various species and feeding types on lipid and fatty acid compositions. In combination with digestive tract content analyses, such information can help clarify the type of feeding mode of the various amphipod species. Micro- and macropredatory amphipod species had only small amounts of triacylglycerols as storage lipids, whereas the deposit-feeder Epimeria georgiana was rich in triacylglycerols (55% of total lipids). The fatty acids 22:6(n-3), 20:5(n-3), 18:1(n-9) and 16:0 were major lipid components of most species. Ampelisca richardsoni, a suspension feeder, had a high amount of 18:4(n-3), a major component of cryptophytes and/or haptophytes, connected with feeding on sedimenting phytoplanktonic material and with a strong bentho-pelagic coupling. In Oradarea edentata, fragments of brown algae were found almost exclusively. The major fatty acid of the macroalgae, 20:4(n-6), replaced the 22:6(n-3) in the phospholipids and triacylglycerols of the amphipod. The sponge eater, Echiniphimedia hodgsoni, was rich in 16:1(n-7) and 18:1(n-7), suggesting that the unidentifiable organic matter was of diatom origin. Eusirus perdentatus, a typical predator, had high proportions of saturated and monounsaturated fatty acids, showing no specialisation in lipid and fatty acid composition. The fatty acid composition of Epimeria georgiana was similar to that of Eusirus perdentatus. However, high levels of triacylglycerols in Epimeria georgiana reflect periodical food plenty and starvation, due to its dependence on dead items. The fatty acid composition of the necrophage Waldeckia obesa was clearly different because of the predominance of 18:1(n-9) (>40% of total fatty acids). This dominance is probably the result of feeding on highly degraded carrion-derived organic matter, which is the major food of W. obesa.