Patterns of stable carbon and nitrogen isotopes in the baleen of common minke whale Balaenoptera acutorostrata from the western North Pacific
Patterns of stable carbon and nitrogen isotopes in the baleen of common minke whale Balaenoptera acutorostrata from the western North Pacific
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DOI：
10.1111/j.1444-2906.2006.01118.x
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发表时间：
2006-02-01
影响因子：
1.9
通讯作者：
Sakamoto, W
中科院分区：
文献类型：
--
作者：
Mitani, Y;Bando, T;Sakamoto, W
测定了来自日本西北太平洋海域的17头普通小须鲸鲸须板以及胃内容物中收集的猎物物种（太平洋磷虾、日本鳀鱼和太平洋秋刀鱼）的稳定碳和氮同位素比，以探讨小须鲸与猎物之间的营养关系。几个三角洲N-15耗尽峰发生沿着的长度鲸须板为10名男性，无论胃内容物（鳕鱼和竹刀鱼）。类似的三角洲N-15耗尽峰也被发现为一个女性和两个未成熟的个人。这些三角洲N-15贫化峰很可能在初夏形成。太平洋秋刀鱼的稳定氮同位素比率（δ N-15）值（9.3 +/- 1.4 ppm）与日本秋刀鱼（8.8 +/- 0.9 ppm）没有显著差异。相比之下，磷虾中的N-15（7月为千分之7.2 +/- 0.5，7月为千分之8.0 +/- 0.2。9月份）明显低于太平洋秋刀鱼。因此，这些峰值可能反映了在鲸鱼的觅食迁移中从磷虾到鱼类的饮食变化。鲸须板的生长速率估计为129毫米/年，看来，大约1.4年的饮食记录留在鲸须板。对于两个未成年的鲸鱼，最大值的Δ N-15发生在须鲸的尖端。这种δ N-15富集可能有助于区分断奶和老年鲸鱼。
Stable carbon and nitrogen isotope ratios were determined in the baleen plates of 17 common minke whales Balaenoptera acutorostrata from the north-western Pacific Ocean off Japan, as well as prey species (krill Euphausia pacifica, Japanese anchovy Engraulis japonicus and Pacific saury Cololabis saira) collected in the stomach contents, to investigate the trophic relationship between the minke whales and their prey. A few delta N-15-depleted peaks occurred along the length of baleen plates for 10 males irrespective of stomach content (anchovies and sauries). Similar delta N-15-depleted peaks were also found for one female and two immature individuals. It was likely that these delta N-15-depleted peaks formed in early summer. The stable nitrogen isotope ratio (delta N-15) values in Pacific saury (9.3 +/- 1.4 parts per thousand) did not differ significantly from that in Japanese anchovy (8.8 +/- 0.9 parts per thousand). In contrast, delta N-15 in krill (7.2 +/- 0.5 parts per thousand in July and 8.0 +/- 0.2 parts per thousand. in September) were significantly lower than in the Pacific saury. Thus, these peaks may reflect the dietary change from krill to fishes in the feeding migration of the whales. Growth rate of the baleen plate was estimated to be 129 mm/y, and it appeared that a dietary record of about 1.4 years remained in the baleen plate. For two immature whales, the maximum value of delta N-15 occurred at the tip of baleen. This delta N-15 enrichment may possibly be useful for discriminating weanlings and older whales.