Gaulke Greg L, Dennis Clark E, Wahl David H, Suski Cory D
Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Fish Physiol Biochem. 2014 Feb;40(1):129-40. doi: 10.1007/s10695-013-9830-6. Epub 2013 Jul 13.
One of the most severe impacts of urbanization on aquatic systems is the increasing presence of low oxygen environments caused by anthropogenic sources of pollution. As urbanization increases nationally and globally, it is becoming exceedingly important to understand how hypoxia affects aquatic fauna, especially fish species. In an effort to better understand the impacts of prolonged hypoxia on fishes, largemouth bass were held at 3.0 and 9.0 mg L⁻¹ for 50 days, which has previously shown to be temporally sufficient to impart plastic phenotypic changes. Following the holding period, fish from each group were subjected to a low dissolved oxygen (DO) challenge of 2.0 mg L⁻¹ for 6 h, and their physiological and hematological parameters were compared with control fish held for 6 h with no change in DO. There were no differences in the physiological stress responses between the two holding groups; however, the low oxygen holding group had increased hemoglobin and hematocrit levels following the 6-h low oxygen challenge compared with the high oxygen group. These results suggest largemouth bass exposed to chronic low oxygen conditions, either naturally or anthropogenically, may possess a beneficial advantage of increased oxygen uptake capacity during periods of low oxygen.
城市化对水生系统最严重的影响之一是人为污染源导致的低氧环境日益增多。随着城市化在国家和全球范围内的加剧，了解缺氧如何影响水生动物，尤其是鱼类，变得极其重要。为了更好地理解长期缺氧对鱼类的影响，大口黑鲈分别在3.0毫克/升和9.0毫克/升的环境中饲养50天，此前的研究表明这段时间足以产生可塑性表型变化。饲养期结束后，每组鱼都要在2.0毫克/升的低溶解氧（DO）环境中接受6小时的挑战，并将它们的生理和血液学参数与在溶解氧无变化的情况下饲养6小时的对照鱼进行比较。两个饲养组之间的生理应激反应没有差异；然而，与高氧组相比，低氧饲养组在6小时低氧挑战后血红蛋白和血细胞比容水平有所升高。这些结果表明，无论是自然还是人为导致的长期低氧条件下，大口黑鲈在低氧时期可能具有增加氧气摄取能力的有益优势。
