Extreme high thermal conditions on tropical rocky shores are challenging to the survival of intertidal ectotherms. Yet, many species are highly successful in these environments in part due to their ability to regulate intrinsic mechanisms associated with physiological stress and their metabolic demand. More recently, there has been a growing awareness that other extrinsic mechanisms, such as animal-associated microbial communities, can also influence the tolerance and survival of ectotherms under stressful conditions. However, the extent to which the intrinsic and extrinsic mechanisms are functionally linked as part of the overall adaptive response of intertidal animals to temperature change and stress is poorly understood. Here, we examined the dynamics and potential interactions of intrinsic and extrinsic mechanisms in the tropical high-supratidal oyster, . We found that oysters modulate their internal biochemistry (oxidized PUFA products, including 5-F-IsoP, 10-F-NeuroP, 13-F-NeuroP, and 16-F-PhytoP) as part of their adaptive regulation to cope with physiological stress during periods of extreme high temperatures when emersed. However, while we detected variation in alpha diversity (ASV richness and Shannon diversity index), dominant microbial taxa and microbial functions across time, no association was found with the host biochemical profiles. The findings here suggest that the thermal condition within oysters can independently influence their intrinsic biochemical responses and extrinsic microbiome profiles. Together, these mechanisms may contribute to the thermal tolerance and survival of the oysters in the challenging conditions of the tropical high-supratidal zone.

中文翻译：

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热波动独立调节热带岩岸牡蛎的生理可塑性和肠道微生物组的动态

热带岩石海岸的极端高温条件对潮间带变温动物的生存构成了挑战。然而，许多物种在这些环境中取得了巨大成功，部分原因是它们能够调节与生理压力和代谢需求相关的内在机制。最近，人们越来越认识到其他外在机制，例如与动物相关的微生物群落，也可以影响变温动物在压力条件下的耐受性和生存。然而，作为潮间带动物对温度变化和压力的整体适应性反应的一部分，内在和外在机制在功能上的联系程度尚不清楚。在这里，我们研究了热带高潮上牡蛎的内在和外在机制的动态和潜在相互作用。我们发现牡蛎调节其内部生物化学（氧化的 PUFA 产品，包括 5-F-IsoP、10-F-NeuroP、13-F-NeuroP 和 16-F-PhytoP），作为其应对生理应激的适应性调节的一部分在极端高温时期出现时。然而，虽然我们检测到α多样性（ASV丰富度和香农多样性指数）、优势微生物类群和微生物功能随时间的变化，但没有发现与宿主生化特征的关联。这里的研究结果表明，牡蛎内的热条件可以独立影响其内在的生化反应和外在的微生物组特征。总之，这些机制可能有助于牡蛎在热带高潮上带的挑战性条件下的耐热性和生存。