Life-history traits of the giant squid Architeuthis dux revealed from stable isotope signatures recorded in beaks
Life-history traits of the giant squid Architeuthis dux revealed from stable isotope signatures recorded in beaks
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DOI：
10.1093/icesjms/fsq091
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发表时间：
2010-10-01
影响因子：
3.3
通讯作者：
Pierce, Graham J.
中科院分区：
文献类型：
--
作者：
Guerra, Angel;Rodriguez-Navarro, Alejandro B.;Pierce, Graham J.
来自比斯开湾和纳米比亚水域的四只巨型鱿鱼大王乌贼的上喙构造了碳和氮同位素剖面，提供了它们饮食的时间整合记录。N-15值为5.5% ~ 13.4%，C-13值为214.4% ~ 217.8%。四种动物的氮同位素剖面在形状上存在显著差异，但δ N-15在每条剖面上都有所增加，在吻端附近的值最低。最低与最高的δ N-15值差异约为5.8%，略小于大小柽柳营养位置的2级差异。δ C-13值的增加不像δ N-15曲线那样明显，但这些变化表明，在生命早期，饮食发生了从营养地位相对较低的较小猎物向营养地位较高的较大猎物的转变。在吻尖附近观察到的δ C-13值的波动可能与相对较小的猎物的碳同位素组成的较大内在变异性和/或生命早期的短暂迁徙行为有关。δ C-13剖面在其剩余寿命中的相对稳定性与成年巨乌贼生活在相对较小的、明确的、多产的区域的假设相一致，这些区域的食物资源具有恒定的碳同位素组成。
Carbon and nitrogen isotope profiles constructed from the upper beaks of four giant squid Architeuthis dux from the Bay of Biscay and Namibian waters provided a time-integrated record of their diet. Values of delta N-15 ranged from 5.5 to 13.4% and of delta C-13 from 214.4 to 217.8%. Nitrogen isotope profiles differed significantly in shape among the four animals analysed, but delta N-15 increased along each profile, with lowest values around the rostral tip. The difference between the lowest and the highest delta N-15 values was similar to 5.8%, slightly less than a two-level difference between the trophic position of small and large A. dux. The increase in delta C-13 values was not as pronounced as for the delta N-15 profiles, but the changes suggest an ontogenetic shift in diet early in life from smaller prey of relatively low trophic status to larger prey of higher status. Fluctuations in delta C-13 values observed near the rostral tip may be associated with a greater intrinsic variability in the carbon isotope composition of relatively small prey, and/or transient migratory behaviour early in life. The relative stability of the delta C-13 profiles over the remainder of their lifespan is consistent with the hypothesis that adult giant squid inhabit relatively small, well-defined, and productive areas, where food resources have a constant carbon isotope composition.