Bowhead whale (Balaena mysticetus) growth and feeding as estimated by δ13C techniques
Bowhead whale (Balaena mysticetus) growth and feeding as estimated by δ13C techniques
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通过 δ13C 技术估算的弓头鲸 (Balaena mysticetus) 生长和摄食
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
N. Haubenstock
中科院分区：
文献类型：
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作者：
D. Schell;S. Saupe;N. Haubenstock
弓头鲸（Balaena mysticetus）的组织 δ13C 随季节变化，以响应白令海、楚科奇海和波弗特海之间每年迁徙路线上消耗的猎物生物 δ13C 的地理变化。 1986 年从阿拉斯加水域捕获的鲸鱼身体 δ13C 的季节性变化提供了一种估算鲸鱼进食的不同栖息地的能量摄入量的方法。成年弓头鲸的肌肉和内脏脂肪的 δ13C 没有表现出明显的季节性变化。与亚成年鲸相比，它们的 13C 浓度更高，这表明它们的大部分食物来自秋季和冬季的进食，或者来自夏季范围内浮游动物富含 13C 的未采样部分。然而，年轻的个体会经历明显的季节变化，这表明它们在夏季和秋季或冬季都大量进食。沿着鲸须长度方向的 δ13C 振荡也可以用来衡量年龄。鲸须的生长速度随着鲸鱼年龄的增长而下降，并提供了一种纠正磨损损失的方法，并允许小于 12 岁的个体衰老。尽管体长并不能很好地反映幼年弓头鲸的年龄，但鲸须的长度却密切相关。第一年之后弓头虫的生长速度很慢（∼ 0.4m yr-1），需要长达 20 年才能达到假定的性成熟长度（13 至 14m）。
Tissue δ13C of bowhead whale, Balaena mysticetus, varies seasonally in response to geographic variations in the δ13C of prey organisms consumed along the annual migratory route between the Bering, Chukchi and Beaufort Seas. Seasonal changes in body δ13C of whales taken in 1986 from Alaskan waters provide a means of estimating energy intake from the different habitats in which the whales feed. Adult bowheads do not show significant seasonal shifts in the δ13C of muscle and visceral fat. Their enrichment in 13C relative to subadult whales suggests that they acquire most of their food from fall and winter feeding or from unsampled parts of the summer range where zooplankton are enriched in 13C. Young individuals however, undergo marked seasonal shifts indicating that they feed heavily both in the summer and autumn or winter. Oscillations in δ13C along the length of the baleen also provide a measure of age. Baleen growth rates decline as the whales age and provide a means of correcting for wear loss and allow aging of individuals less than ∼ 12 yr old. Although body length is a poor indicator of age in young bowhead whales, baleen length is closely correlated. Growth rates of bowheads after Year 1 are slow (∼ 0.4m yr-1) and up to 20 yr are required to reach the assumed length of sexual maturity at 13 to 14m.