Documenting the settlement history of individual fish larvae using stable isotope ratios: model development and validation
Documenting the settlement history of individual fish larvae using stable isotope ratios: model development and validation
复制标题
DOI：
10.1016/s0022-0981(01)00324-0
复制
发表时间：
2001-10-15
影响因子：
2
通讯作者：
Holt, GJ
中科院分区：
文献类型：
--
作者：
Herzka, SZ;Holt, SA;Holt, GJ
三角洲C-13和/或三角洲N-15的新定居的鱼苗应该改变从浮游生物的签名，反映河口的食物来源，从浮游到底层托儿所栖息地解决。三角洲C-13和三角洲N-15的测量的基础上的经验模型被用来估计的大小在解决（L-sett）和时间，因为解决（T-sett）的红鼓（美国石首鱼;石首鱼科），河口依赖的物种，其幼虫从沿海地区迁移到浅海草栖息地在河口。该模型依赖于（1）幼虫的同位素组成之前的饮食转换和平衡到一个新的食物来源，（2）生长速度的测量和（3）估计的同位素变化的代谢周转的贡献。为了测试该模型，模拟沉降事件转移沉降大小的幼虫（6毫米标准长度; SL）饲养在实验室部署在苗圃栖息地在阿兰瑟斯河口，得克萨斯州，美国的笼子。δ C-13和δ N-13的大部分变化（约。在15天的研究期内发生的同位素变化（两者均为10 ppm）归因于生长，尽管代谢周转显著加速了同位素变化的速率。当将生长和代谢周转纳入模型时，生成了L-sett（1 mm SL内）和T-sett（1-2天内）的准确估计值。野生捕获的前和后定居幼虫收集在2周的时间内的同位素组成的特点。尽管存在时间差异，但潜在定居者的C-13三角洲和N-15三角洲随大小和采样位置的变化很小（<千分之1）。在部分研究期间，新定居的幼虫（千分之19.3）和已经平衡到河口食物的“大”个体（千分之16.5）之间的δ C-13存在明显差异。氮不能作为一种示踪剂的解决，由于没有在三角洲N-15的前和后结算幼虫的差异。碳数据被用来估计自定居以来的规模和时间。野生捕捞鱼类最丰富的L-sett是5-6 mm SL。使用公布的增长率后解决红鼓在研究领域，据估计，解决事件发生在连续几天。估计的大小和时间，因为解决是敏感的代谢周转的影响，同位素组成的沉降前的红鼓和增长率。利用稳定的同位素比率可以更好的时间分辨率的海洋鱼类的定居动态。(C)2001 Elsevier Science B. V.保留所有权利。
The delta C-13 and/or delta N-15 of newly settled fish larvae should change from a planktonic signature to one reflecting estuarine food sources following settlement from pelagic to demersal nursery habitat. An empirical model based on measurements of delta C-13 and delta N-15 was used to estimate size at settlement (L-sett) and time since settlement (T-sett) for red drum (Sciaenops ocellatus; Sciaenidae), an estuarine-dependent species whose larvae migrate from coastal areas to shallow seagrass habitat in estuaries. The model relies on (1) the isotopic composition of the larvae prior to a dietary switch and following equilibration to a new food source, (2) growth rate measurements and (3) estimates of the contribution of metabolic turnover to isotopic change. To test the model, a settlement event was simulated by transferring settlement-size larvae (6 mm standard length; SL) reared in the laboratory to cages deployed in nursery habitat in the Aransas Estuary, TX, USA. Most of the changes in delta C-13 and delta N-13 (ca. 10 parts per thousand for both) occurring over the 15-day study period were attributed to growth, although metabolic turnover significantly accelerated the rate of isotopic change. When growth and metabolic turnover were incorporated into the model, accurate estimates of L-sett (within 1 mm SL) and T-sett (within 1-2 days) were generated. The isotopic composition of wild-caught pre- and post-settlement larvae collected during a 2-week period was also characterized. Variability in the delta C-13 and delta N-15 of potential settlers as a function of size and sampling location was small (< 1 parts per thousand), although there were temporal differences. For part of the study period, there was a distinct difference between the delta C-13 of newly settled larvae (-19.3 parts per thousand) and "large" individuals that had equilibrated to estuarine foods (-16.5 parts per thousand). Nitrogen could not be used as a tracer of settlement due to the absence of differences in delta N-15 of pre- and post-settlement larvae. The carbon data was used to estimate size and time since settlement. The most abundant L-sett for wild-caught fish was 5-6 mm SL. Using published growth rates for post-settlement red drum in the study area, it was estimated that settlement events occurred over several consecutive days. The estimates of size and time since settlement were sensitive to the effect of metabolic turnover, the isotopic composition of pre-settlement red drum and growth rate. Utilization of stable isotope ratios allows for the finer temporal resolution of the settlement dynamics of marine fish species. (C) 2001 Elsevier Science B.V. All rights reserved.