Fishes of the Amazon: diversity and beyond

Abstract: The Amazon basin houses a particular group of freshwater organisms, whose study tells the geological history of the region, how biological diversity was shaped, how it is maintained, and what it hides. The fish of the Amazon is represented by more than 3,000 known species distributed from the basal groups up to the more specialized ones. This species richness hides a diversity of adaptations that are dispersed at all levels of the biological organization. In this summary of the conference delivered at the Brazil-France Bilateral Symposium, held in Manaus in 2018, we describe two aspects of the hidden world of adaptive diversity: adaptations to changes in dissolved oxygen and the abilities of the Rio Negro fish to face acidic and ion-poor waters of their habitats. Also, we present the vulnerability of Amazonian fish to ongoing climate changes. Then, very briefly, we call attention to the many hidden biological processes that allow these fish species to survive their environments, much of which is unknown. Indeed, however, they are intricately related to men, either by responding to environmental disturbances that we have caused, or by containing information that contributes to improving the quality of the environment in which we live.

摘要：亚马孙流域栖息着一类独特的淡水生物类群，对其开展研究能够揭示该区域的地质演化历史、生物多样性的塑造与维持机制，以及其暗藏的诸多未解奥秘。目前已知亚马孙鱼类物种超过3000种，涵盖从系统发育基部类群到高度特化类群的各个演化分支。这类物种丰富度背后暗藏着多样的适应性特征，这些特征贯穿生物组织的所有层级。本摘要基于2018年于马瑙斯举办的巴法双边研讨会的会议报告，我们在此阐述适应性多样性隐秘维度的两个方面：一是对溶解氧浓度变化的适应性机制，二是内格罗河（Rio Negro）鱼类应对栖息地酸性贫离子水环境的能力。此外，我们还探讨了亚马孙鱼类对当前气候变化的脆弱性。最后，我们简要提请关注那些助力这些鱼类适应栖息环境的诸多隐秘生物学过程，其中绝大多数机制尚未被人类探明。诚然，这些鱼类与人类之间存在错综复杂的关联：它们既会响应人类活动引发的环境扰动，其所携带的生物学信息也能够为改善人类赖以生存的环境质量提供重要支撑。