亚马逊是世界上所有淡水鱼物种的15%(>2700,按18个顺序)的家园,许多是该地区特有的,有6500万年的进化历史,占排放到海洋的淡水总量的20%。这些特点使亚马逊成为世界上一个独特的地区。我们回顾了环境的地质历史,它目前的生物地球化学和进化力量导致了目前特有的鱼类物种分布在三种非常不同的水类型中:黑水[酸性,离子差,富含溶解有机碳(DOC)],白色水域(环绕,富含颗粒的)和清澈的水域(环绕中性,离子差,DOC-poor)。每年的洪水脉冲是鱼类的主要生态驱动力,提供喂养,繁殖和迁徙机会,并深刻影响O2、CO2和DOC制度。由于气候变化和其他人为压力,如森林砍伐,污染和政府管理不善,亚马逊现在正处于危机之中。环境变得越来越干燥,现在正在发生更强烈和更频繁的洪水脉冲,高水位和低水位之间的差异更大。目前的预测是,亚马逊水域在不久的将来会更热,酸性更强,更暗(即更多的DOC,更多的悬浮颗粒),更高的离子,CO2含量较高,O2含量较低,具有许多协同作用。我们回顾了亚马逊鱼的当前生理信息,专注于处理酸性和贫离子环境的温度耐受性和离子调节策略。我们还讨论了DOC和粒子对ill功能的影响,高溶解CO2和低溶解O2的影响,重点是水与空气呼吸机制,和pH补偿策略。我们得出结论,未来水温升高将是最关键的因素,消灭许多物种。气候变化可能会有利于常规代谢率低的主要呼吸水的物种,常规代谢率的低温敏感性,高厌氧能力,耐缺氧能力高,耐热性高。
Amazonia is home to 15% (>2700, in 18 orders) of all the freshwater fish species of the world, many endemic to the region, has 65 million years of evolutionary history and accounts for 20% of all freshwater discharge to the oceans. These characteristics make Amazonia a unique region in the world. We review the geological history of the environment, its current biogeochemistry and the evolutionary forces that led to the present endemic fish species that are distributed amongst three very different water types: black waters [acidic, ion-poor, rich in dissolved organic carbon (DOC)], white waters (circumneutral, particle-rich) and clear waters (circumneutral, ion-poor, DOC-poor). The annual flood pulse is the major ecological driver for fish, providing feeding, breeding and migration opportunities, and profoundly affecting O2, CO2 and DOC regimes. Owing to climate change and other anthropogenic pressures such as deforestation, pollution and governmental mismanagement, Amazonia is now in crisis. The environment is becoming hotter and drier, and more intense and frequent flood pulses are now occurring, with greater variation between high and low water levels. Current projections are that Amazon waters of the near future will be even hotter, more acidic, darker (i.e. more DOC, more suspended particles), higher in ions, higher in CO2 and lower in O2, with many synergistic effects. We review current physiological information on Amazon fish, focusing on temperature tolerance and ionoregulatory strategies for dealing with acidic and ion-poor environments. We also discuss the influences of DOC and particles on gill function, the effects of high dissolved CO2 and low dissolved O2, with emphasis on water- versus air-breathing mechanisms, and strategies for pH compensation. We conclude that future elevations in water temperature will be the most critical factor, eliminating many species. Climate change will likely favour predominantly water-breathing species with low routine metabolic rates, low temperature sensitivity of routine metabolic rates, high anaerobic capacity, high hypoxia tolerance and high thermal tolerance.