Department of Zoology and Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada, VT6 1Z4.
Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
J Exp Biol. 2022 Jun 1;225(11). doi: 10.1242/jeb.244239. Epub 2022 Jun 6.
The hypoxic constraint on peak oxygen uptake (ṀO2,peak) was characterized in rainbow trout over a range of ambient oxygen tensions with different testing protocols and statistical models. The best-fit model was selected using both statistical criteria (R2 and AIC) and the model's prediction of three anchor points for hypoxic performance: critical PO2 (Pcrit), maximum ṀO2 and a new metric, the minimum PO2 that supports 50% of absolute aerobic scope (PAAS-50). The best-fitting model was curvilinear using five strategically selected PO2 values. This model predicted PAAS-50 as 70 mmHg (coefficient of variation, CV=9%) for rainbow trout. Thus, while a five-point hypoxic performance curve can characterize the limiting effects of hypoxia in fish, as envisaged by Fry over 75 years ago, PAAS-50 is a promising metric to compare hypoxic constraints on performance in a standardized manner both within and across fish species.
本研究采用不同的测试方案和统计模型，在一系列环境氧张力下对虹鳟鱼的最大摄氧量峰值（ṀO2,peak）的缺氧限制进行了特征描述。通过统计标准（R2 和 AIC）和模型对缺氧性能的三个锚定点（临界氧分压（Pcrit）、最大 ṀO2 和新指标绝对需氧范围的 50%所支持的最低氧分压（PAAS-50）的预测，选择了最佳拟合模型。最佳拟合模型使用五个有策略选择的 PO2 值呈曲线关系。该模型预测虹鳟鱼的 PAAS-50 为 70mmHg（变异系数，CV=9%）。因此，尽管 75 多年前 Fry 提出的五点缺氧性能曲线可以描述鱼类缺氧的限制作用，但 PAAS-50 是一种很有前途的指标，可以在种内和种间以标准化的方式比较缺氧对性能的限制作用。
