Distribution of Themisto (Amphipoda) spp in the Barents Sea and predator-prey interactions
Distribution of Themisto (Amphipoda) spp in the Barents Sea and predator-prey interactions
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DOI：
10.1006/jmsc.2001.1078
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发表时间：
2001-08-01
影响因子：
3.3
通讯作者：
Mehl, S
中科院分区：
文献类型：
--
作者：
Dalpadado, P;Borkner, N;Mehl, S
Themisio abyssorum 和 Themisto libellula 是 1984 年至 1996 年间在巴伦支海中部和北部观察到的主要片脚类物种。 T. abyssorum 在亚北极水域占主导地位，T. libellula 在北极水域占主导地位。第三种，Themisto compressa，很稀有，仅限于大西洋水域。我们的研究显示，T. abyssorum 和 T. libellula 在夏季和初秋达到峰值丰度。高丰度通常与极锋水域有关。 7：libellula 比 T abyssorum 具有更接近表面的分布。 1985年至1987年间，随着毛鳞鱼种群的减少，Themisto abyssorum和T libellula的丰度却有所增加，这可能是由于毛鳞鱼（Mallotus villosus）放牧压力的减少。在 20 世纪 80 年代中期和 90 年代，当毛鳞鱼数量处于极低水平时，鳕鱼 (Gadus morhua) 从毛鳞鱼转向其他猎物，例如片足类动物和磷虾。 1984-1999年对鳕鱼胃中片脚类动物的详细分析表明，反刍鱼主要以Themisto spp.为食，尤其是7. libellula。大多数年龄段的鳕鱼都捕食Themisto 物种。 1987-1991 年间，随着毛鳞鱼种群的增加，观察到 Themisto abyssorum 和 T. libellula 的丰度相应减少。 1993-1996年间，毛鳞鱼种群再次处于低水平，这两种片脚类物种的丰度有所增加。 20 世纪 90 年代中期，T. libellula 丰度的增加不太明显，这可能是由于鳕鱼和竖琴海豹 (Phoca groenlandica) 和北极海鸟等其他捕食者的更大的放牧压力。 20 世纪 90 年代中期的鳕鱼存量约为 80 年代中期的两倍。这些结果说明了巴伦支海中片脚类等大型浮游动物与毛鳞鱼和鳕鱼之间存在强烈的捕食者-猎物相互作用。巴伦支海的片脚类动物种群似乎在很大程度上受到捕食的控制。
Themisio abyssorum and Themisto libellula were the dominant amphipod species observed in the central and the northern Barents Sea during 1984-1996. T abyssorum was predominant in the subarctic waters, T. libellula in the Arctic waters. A third species, Themisto compressa, was rare and was restricted to the Atlantic waters. Our study showed peak abundances of T. abyssorum and T libellula in summer and in early autumn. High abundances were usually associated with Polar Front waters. 7: libellula has a more near surface distribution than T abyssorum. Followed by a decrease in the capelin stock from 1985-1987 there was an increase in the abundance of Themisto abyssorum and T libellula, probably due to the reduced grazing pressure from capelin (Mallotus villosus). In the mid-1980s and 1990s when the capelin stuck was at extremely low levels, cod (Gadus morhua) switched from capelin to alternative prey such as amphipods and krill. Detailed analysis of amphipods in the cod stomachs from 1984-1999, showed that cud fed mainly on Themisto spp.. especially on 7. libellula. Themisto species were consumed by most age groups of cod. With an increase in the capelin stock from 1987-1991, a corresponding decrease in the abundance of Themisto abyssorum and T. libellula was observed. During 1993 1996 when the capelin stock again was at low levels, the abundance of these two amphipod species increased. The increase in abundance was less pronounced in the mid-1990s for T. libellula probably owing to higher grazing pressure from cod and other predators such as harp seal (Phoca groenlandica) and arctic sea birds. The stock size of cod in the mid-1990s was about twice the amount as in the mid-1980s. These results illustrate strong predator-prey interactions between macrozooplankton species as amphipods and capelin and cod in the Barents Sea. The amphipod populations in the Barents Sea appear to be to a large extent controlled by predation.