Table_2_Microbiome Composition and Function in Aquatic Vertebrates: Small Organisms Making Big Impacts on Aquatic Animal Health.XLSX

Aquatic ecosystems are under increasing stress from global anthropogenic and natural changes, including climate change, eutrophication, ocean acidification, and pollution. In this critical review, we synthesize research on the microbiota of aquatic vertebrates and discuss the impact of emerging stressors on aquatic microbial communities using two case studies, that of toxic cyanobacteria and microplastics. Most studies to date are focused on host-associated microbiomes of individual organisms, however, few studies take an integrative approach to examine aquatic vertebrate microbiomes by considering both host-associated and free-living microbiota within an ecosystem. We highlight what is known about microbiota in aquatic ecosystems, with a focus on the interface between water, fish, and marine mammals. Though microbiomes in water vary with geography, temperature, depth, and other factors, core microbial functions such as primary production, nitrogen cycling, and nutrient metabolism are often conserved across aquatic environments. We outline knowledge on the composition and function of tissue-specific microbiomes in fish and marine mammals and discuss the environmental factors influencing their structure. The microbiota of aquatic mammals and fish are highly unique to species and a delicate balance between respiratory, skin, and gastrointestinal microbiota exists within the host. In aquatic vertebrates, water conditions and ecological niche are driving factors behind microbial composition and function. We also generate a comprehensive catalog of marine mammal and fish microbial genera, revealing commonalities in composition and function among aquatic species, and discuss the potential use of microbiomes as indicators of health and ecological status of aquatic ecosystems. We also discuss the importance of a focus on the functional relevance of microbial communities in relation to organism physiology and their ability to overcome stressors related to global change. Understanding the dynamic relationship between aquatic microbiota and the animals they colonize is critical for monitoring water quality and population health.

水生生态系统正面临日益加剧的全球人为与自然变化带来的胁迫，涵盖气候变化、富营养化、海洋酸化与污染等诸多问题。本批判性综述系统性综合了水生脊椎动物微生物群（microbiota）的相关研究，并通过有毒蓝藻与微塑料两个案例，探讨新兴胁迫因子对水生微生物群落的影响。截至目前，多数研究仅聚焦于单一宿主的宿主相关微生物群，但鲜有研究采用整合视角，在生态系统层面同时考量宿主相关与自由生活的微生物群，以此解析水生脊椎动物的微生物群落。本综述梳理了当前学界对水生生态系统中微生物群的认知，重点关注水体、鱼类与海洋哺乳动物之间的微界面。尽管水体中的微生物群落会随地理、温度、深度等因素发生变化，但核心微生物功能（如初级生产、氮循环与营养代谢）在各类水生环境中往往具有保守性。本综述还阐述了鱼类与海洋哺乳动物组织特异性微生物群落的组成与功能相关认知，并探讨了影响其群落结构的环境因子。水生哺乳动物与鱼类的微生物群具有高度的物种特异性，宿主体内的呼吸道、皮肤与胃肠道微生物群之间维持着精妙的平衡。对于水生脊椎动物而言，水体环境与生态位是塑造其微生物群落组成与功能的核心驱动因素。本研究还构建了一套涵盖海洋哺乳动物与鱼类微生物属类的全面目录，揭示了水生物种在微生物组成与功能上的共性，并探讨了微生物群落作为水生生态系统健康与生态状态指示物的应用潜力。此外，本综述还强调了聚焦微生物群落与宿主生理功能的相关性，以及其应对全球变化相关胁迫的能力的重要性。解析水生微生物群与其宿主动物之间的动态互作关系，对于监测水体质量与种群健康至关重要。