Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4
Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4.
Biol Lett. 2017 Nov;13(11). doi: 10.1098/rsbl.2017.0392.
Anthropogenic increases in global temperature and agricultural runoff are increasing the prevalence of aquatic hypoxia throughout the world. We investigated the potential for a relatively rapid evolution of hypoxia tolerance using two isolated (for less than 11 000 years) populations of threespine stickleback: one from a lake that experiences long-term hypoxia (Alta Lake, British Columbia) and one from a lake that does not (Trout Lake, British Columbia). Loss-of-equilibrium (LOE) experiments revealed that the Alta Lake stickleback were significantly more tolerant of hypoxia than the Trout Lake stickleback, and calorimetry experiments revealed that the enhanced tolerance of Alta Lake stickleback may be associated with their ability to depress metabolic rate (as indicated by metabolic heat production) by 33% in hypoxia. The two populations showed little variation in their capacities for O extraction and anaerobic metabolism. These results reveal that intraspecific variation in hypoxia tolerance can develop over relatively short geological timescales, as can metabolic rate depression, a complex biochemical response that may be favoured in long-term hypoxic environments.
人为引起的全球温度升高和农业径流增加，正在使世界各地水生缺氧的流行程度增加。我们使用两个孤立的（少于 11000 年）的三刺鱼种群来研究对缺氧的耐受性的快速进化的潜力：一个来自长期缺氧的湖泊（不列颠哥伦比亚省的阿尔塔湖），另一个来自没有缺氧的湖泊（不列颠哥伦比亚省的鳟鱼湖）。失去平衡（LOE）实验表明，阿尔塔湖的棘鱼比鳟鱼湖的棘鱼更能耐受缺氧，而量热实验表明，阿尔塔湖棘鱼的耐受性增强可能与其在缺氧条件下降低代谢率（以代谢产热表示）33%的能力有关。两个种群在提取氧气和无氧代谢的能力方面几乎没有差异。这些结果表明，在相对较短的地质时间尺度内，耐缺氧性的种内变异可以发展，就像代谢率降低一样，这是一种复杂的生化反应，可能在长期缺氧环境中受到青睐。
