Stable isotope turnover in blood and claws: A case study in captive African Penguins
Stable isotope turnover in blood and claws: A case study in captive African Penguins
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DOI：
10.1016/j.jembe.2013.06.021
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发表时间：
2013-10-01
影响因子：
2
通讯作者：
Ryan, Peter G.
中科院分区：
文献类型：
--
作者：
Barquete, Viviane;Strauss, Venessa;Ryan, Peter G.
稳定同位素比值（C-13:C-12和N-15:(IN)-I-14）越来越多地被用于推断鸟类的运动和营养位置信息。羽毛、血液、肌肉、骨骼和其他组织经常被采样，从而可以在一定的时间尺度上了解组织特定的周转率。非破坏性取样通常仅限于羽毛和血液，但一些研究也使用了爪子。采用人工饲养的非洲企鹅（Spheniscus demersus）为研究对象，对其爪、血、血浆和红细胞的周转率和识别因子（delta = delta（组织）- delta（饲料））进行了实验研究。之前以沙丁鱼（沙丁鱼sagax）为食的8只企鹅在49天内改为以小黑鲈（Merluccius paradoxus/capensis）为食。两种鱼的N-15值不同，但C-13值无差异。血液及其组分的半衰期与其他研究报告的半衰期相似，血浆的周转率（7.6 +/- 0.7天）比红细胞（14.3 +/- 1.6天）更快。爪的平均生长速度为0.8±0.2 mm /周（-1），这表明企鹅指甲的可见部分大约需要126天才能被替换。然而，尽管在饮食转换后对指甲进行了157天的监测，但没有检测到氮同位素值的变化。不同组织的辨别因素各不相同，爪子的辨别因素最低：δ N-15（爪-沙丁鱼）= +1.5 +/- 0.7‰。虽然可以对爪子进行非破坏性取样，但在进行同位素分析时需要谨慎使用，因为它们似乎对中短期饮食变化相对不敏感。(C) 2013 Elsevier B.V.版权所有
Stable isotope ratios (C-13:C-12 and N-15:(IN)-I-14) increasingly are being used to infer information about the movements and trophic positions of birds. Feathers, blood, muscle, bone and other tissues frequently are sampled, allowing insights at a range of temporal scales, linked to tissue-specific turnover rates. Non-destructive-sampling typically is limited to feathers and blood, but some studies have used claws. An experiment was performed manipulating the diet of captive African Penguins (Spheniscus demersus) to test the turnover rates and discrimination factors (delta = delta(tissue) - delta(diet)) of claws, blood, plasma and erythrocytes. Eight penguins previously fed sardines (Sardinops sagax) were switched to a diet of small hakes (Merluccius paradoxus/capensis) for 49 days. The two fish differed in their N-15 values but not C-13. Blood and its fractions had half-lives similar to those reported in other studies, with plasma showing a faster turnover rate (7.6 +/- 0.7 days) than erythrocytes (14.3 +/- 1.6 days). Claw growth averaged 0.8 +/- 0.2 mm week(-1), suggesting that the visible portion of penguin nail takes approximately 126 days to be replaced. However, no shift in the nitrogen isotope value was detected, despite monitoring nails for 157 days after the diet switch. Discrimination factors varied among tissues, with claws having the lowest factor: delta N-15(claw-sardine) = +1.5 +/- 0.7 parts per thousand. Although claws can be sampled non-destructively, they need to be used with caution for isotope analyses because they appear to be relatively insensitive to short to medium-term diet shifts. (C) 2013 Elsevier B.V. All rights reserved.