Lipid biomarkers indicate different ecological niches and trophic relationships of the Arctic hyperiid amphipods Themisto abyssorum and T-libellula
Lipid biomarkers indicate different ecological niches and trophic relationships of the Arctic hyperiid amphipods Themisto abyssorum and T-libellula
复制标题
DOI：
10.1007/s00300-001-0354-7
复制
发表时间：
2002-05-01
期刊：
影响因子：
1.7
通讯作者：
Hagen, W
中科院分区：
文献类型：
--
作者：
Auel, H;Harjes, M;Hagen, W
Themisto libellula和T.深海囊藻是北极远洋生态系统的重要组成部分。这两个物种都是肉食性的，捕食中型浮游动物。它们是海洋脊椎动物的重要食物来源，也是浮游动物次级生产和更高营养级之间的关键环节。本文报道了中国对虾的总脂含量、脂类和脂肪酸组成。libellula和T.来自北方弗拉姆海峡北部和北冰洋中部的深海藻。这两个物种都有中度至高脂质含量的14-42%的身体干重。于T.总脂含量与体质量呈显著正相关，而T. libellula表现出与性别相关的差异，脂质含量。尽管它们的体型较小，但T。libellula的脂肪含量高于男性。蜡酯代表了这两个物种中的主要脂质类别，占总脂质的41-43%，而三酰甘油占23- 32%。脂肪酸组成主要由长链多不饱和部分20：5（n-3）和22：6（n-3）、短链饱和化合物（16：0和14：0）和不同长度的单不饱和脂肪酸（即16：1（n-7）、20：1（n-9）、18：1（n-9）和22：1（n-11）组成。脂肪酸和酒精模式的物种特异性和地理差异显然与饮食和生命周期的差异有关。T.中含有大量的脂肪酸和醇20：1（n-9）和22：1（n-11）。libellula表明捕食食草哲水蚤桡足类。另外。20：5（n-3）在T. libellula的研究表明，冰藻的生产与低温-水层耦合过程（即海冰和水层群落之间的交换过程）对这一高北极上层物种的营养有着密切的联系。与此相反，T.深海藻的特征在于20：5（n-3）的量较低，并且其生物标志物比率指示较高的营养级。这与T. abyssorum及其在北冰洋深层的存在。在那里它可能以杂食性和/或食肉性猎物为食。
The hyperiid amphipods Themisto libellula and T. abyssorum are important components of Arctic pelagic ecosystems. Both species are carnivorous and prey on mesozooplankton. They represent a substantial food source for marine vertebrates and are a key link between zooplankton secondary production and higher trophic levels. We present data on the total lipid content, lipid class and fatty acid composition of T. libellula and T. abyssorum from northern Fram Strait and the central Arctic Ocean. Both species had moderate to high lipid contents of 14-42% of body dry mass. In T. abyssorum, total lipid content was correlated to body mass, while T. libellula showed sex-related differences in lipid content. Despite their smaller body size, females of T. libellula had higher lipid contents than males. Wax esters represented the major lipid class in both species with 41-43% of total lipid, while triacylglycerols contributed 23-32%. The fatty acid composition was dominated by the long-chain polyunsaturated moieties 20:5(n-3) and 22:6(n-3), short-chain saturated compounds (16:0 and 14:0) and monounsaturated fatty acids of varying length, i.e. 16:1(n-7), 20:1(n-9), 18:1(n-9) and 22:1(n-11). Species-specific and geographic variations in the fatty acid and alcohol patterns were apparently linked to differences in diet and life-cycle. High amounts of the fatty acids and alcohols 20:1(n-9) and 22:1(n-11) in T. libellula indicate predation on herbivorous Calanus copepodids. In addition. elevated levels of 20:5(n-3) in T. libellula indicate a close connection with ice-algal production and the importance of cryo-pelagic coupling processes (i.e. exchange processes between the sea ice and the pelagic communities) for the nutrition of this high-Arctic epipelagic species. In contrast, T. abyssorum is characterised by lower amounts of 20:5(n-3) and its biomarker ratios indicate a higher trophic level. This observation is consistent with the subarctic-boreal origin of T. abyssorum and its occurrence in deeper layers of the Arctic Ocean. where it may feed on omnivorous and/or carnivorous prey.