Routine respiration rates in the South Georgia stock of Antarctic krill (Euphausia superba) were measured to compare with previously published measurements on stocks from colder locations further south. Within the natural temperature range of this species (− 1.8° to 5.5 °C), respiration rate data from both the present and previous studies were adequately fitted by a single Arrhenius regression (Q10 of 2.8), although South Georgia krill showed an upward deviation from this regression between 0° and 2 °C (the lower temperature range at South Georgia). Metabolic compensation (i.e. the comparative lowering of respiration rate) at the high temperatures experienced at South Georgia was not apparent, although the higher than predicted metabolic rates at low temperatures suggests acclimation of South Georgia krill to a warm water lifestyle. Weight-specific respiration rate was significantly higher in sub-adults and adults compared to juveniles, highlighting the metabolic burden of reproduction. South Georgia krill showed no further increase in respiration rate when exposed to acute temperatures (5.5–12.2 °C), indicating that they were already at the limit of aerobic capacity by 5.5 °C. Overall, this study shows that even small degrees of additional warming to South Georgia waters are likely to make conditions there metabolically unsustainable for Antarctic krill.

中文翻译：

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南乔治亚水域南极磷虾（Euphausia superba）的常规代谢：在其范围边缘缺乏代谢补偿

测量了南乔治亚州南极磷虾 (Euphausia superba) 种群的常规呼吸速率，以与先前公布的对来自更南部较冷地区的种群的测量结果进行比较。在该物种的自然温度范围内（- 1.8° 至 5.5 °C），尽管南乔治亚磷虾表现出向上偏差，但通过单个 Arrhenius 回归（Q10 为 2.8）充分拟合了当前和以前研究的呼吸速率数据从 0° 到 2°C（南乔治亚的较低温度范围）之间的回归。南乔治亚岛经历的高温下的代谢补偿（即呼吸率的相对降低）并不明显，尽管在低温下高于预测的代谢率表明南乔治亚磷虾适应了温水生活方式。与青少年相比，亚成人和成人的体重特定呼吸率显着更高，突出了繁殖的代谢负担。南乔治亚磷虾在暴露于急性温度 (5.5–12.2 °C) 时没有表现出呼吸率进一步增加，这表明它们的有氧能力已经达到了 5.5 °C 的极限。总体而言，这项研究表明，即使南乔治亚岛水域出现小幅度的额外变暖，也可能使南极磷虾的代谢环境不可持续。表明他们已经达到了 5.5 °C 的有氧能力极限。总体而言，这项研究表明，即使南乔治亚岛水域出现小幅度的额外变暖，也可能使南极磷虾的代谢环境不可持续。表明他们已经达到了 5.5 °C 的有氧能力极限。总体而言，这项研究表明，即使南乔治亚岛水域出现小幅度的额外变暖，也可能使南极磷虾的代谢环境不可持续。