Tissue-specific turnover rates of the nitrogen stable isotope as functions of time and growth in a cyprinid fish
Tissue-specific turnover rates of the nitrogen stable isotope as functions of time and growth in a cyprinid fish
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DOI：
10.1007/s10750-017-3276-2
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发表时间：
2018-01-01
期刊：
影响因子：
2.6
通讯作者：
Britton, J. Robert
中科院分区：
文献类型：
--
作者：
Busst, Georgina M. A.;Britton, J. Robert
稳定同位素数据的生态应用需要了解组织的同位素周转率，通常称为同位素半衰期（T（0.5））或质量变化（G（0.5））。生态研究越来越多地分析非破坏性收集的组织，如鱼鳍和鱼鳞，但对其周转率的了解有限。确定原地更替率具有挑战性，最好采用非原地办法。相应地，使用饮食转换实验确定了幼须（5.5 +/-0.6 g起始重量）的氮稳定同位素（Δ N-15）的T（0.5）和G（0.5）。在饮食转换后的125天期间，从肌肉、鳍和鳞中获取Δ N-15数据。虽然在125天内没有达到同位素平衡，但Δ N-15值确实接近新饮食的值。最快的周转率是在代谢更活跃的组织，从肌肉（最高）到鳞片（最低）。周转率相对较慢; T（0.5）为84（肌肉）至145（鳞片）天; G（0.5）为1.39 x体重（肌肉）至2.0 x体重（鳞片），这可能与实验鱼的缓慢生长有关。这些营业额估计在不同的组织强调的重要性，估计半衰期的重点类群在物种和组织水平的生态研究。
Ecological applications of stable isotope data require knowledge on the isotopic turnover rate of tissues, usually described as the isotopic half-life in days (T (0.5)) or the change in mass (G (0.5)). Ecological studies increasingly analyse tissues collected non-destructively, such as fish fin and scales, but there is limited knowledge on their turnover rates. Determining turnover rates in situ is challenging, with ex situ approaches preferred. Correspondingly, T (0.5) and G (0.5) of the nitrogen stable isotope (delta N-15) were determined for juvenile barbel Barbus barbus (5.5 +/- 0.6 g starting weight) using a diet-switch experiment. delta N-15 data from muscle, fin and scales were taken during a 125 day post diet-switch period. Whilst isotopic equilibrium was not reached in the 125 days, the delta N-15 values did approach those of the new diet. The fastest turnover rates were in more metabolically active tissues, from muscle (highest) to scales (lowest). Turnover rates were relatively slow; T (0.5) was 84 (muscle) to 145 (scale) days; G (0.5) was 1.39 x body mass (muscle) to 2.0 x body mass (scales), with this potentially relating to the slow growth of the experimental fish. These turnover estimates across the different tissues emphasise the importance of estimating half-lives for focal taxa at species and tissue levels for ecological studies.