Nano-titanium dioxide (nano-TiO₂) is a ubiquitous contaminant in the marine environment that accumulates in sediments and biological tissues. Coupled with global warming, these challenges can enhance the deleterious properties of nano-TiO₂, leading to compounded pollution effects on marine life and ecosystems. This study investigated the effects of nano-TiO₂ and increased temperatures on the Japanese swimming crab's gut microbiota and digestive system, Charybdis japonica, through different scenarios. We employed three exposure scenarios: direct exposure (DE) of the crabs to warming and nano-TiO₂, indirect exposure (IE) through consumption of mussels Mytilus coruscus subjected to the same conditions, and combined exposure (CE), where crabs were directly exposed to warming and nano-TiO₂ while consuming affected mussels. Additionally, a control group was established, comprising Japanese crab C. japonica and thick-shelled mussel M. coruscus that were reared under standard temperature (22 °C, the average annual temperature in the region where the mussels and crabs were sampled) and 0 mg L⁻¹ nano-TiO₂ concentration conditions. The findings indicated that warming and nano-TiO₂ disrupted the crabs' ATP production, digestive responses, and body chemical composition, leading to intestinal flora dysfunction. Notably, nano-TiO₂ exerted a stronger impact on the crabs' digestive enzymes and intestinal flora than warming alone; however, the concurrent presence of warming and nano-TiO₂, especially under the direct exposure (DE) conditions, generally exacerbated the negative effects of nano-TiO₂. This research provides valuable insights into the implications of nano-TiO₂ and elevated temperature on the digestive responses of marine crabs.

中文翻译：

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纳米二氧化钛和高温通过基于贻贝的食物链损害螃蟹的肠道健康


纳米二氧化钛（nano-TiO ₂ ）是海洋环境中普遍存在的污染物，在沉积物和生物组织中积累。再加上全球变暖，这些挑战可能会增强纳米TiO ₂的有害特性，导致对海洋生物和生态系统的复合污染影响。本研究通过不同的场景研究了纳米 TiO ₂和升高的温度对日本梭子蟹肠道微生物群和消化系统Charybdis japonica的影响。我们采用了三种暴露场景：将螃蟹直接暴露于变暖和纳米TiO ₂中，通过食用相同条件下的贻贝进行间接暴露（IE），以及将螃蟹直接暴露在联合暴露（CE）中。在食用受影响的贻贝时暴露于变暖和纳米TiO ₂ 。此外，还建立了对照组，包括在标准温度（22℃，贻贝和螃蟹采样地区的年平均温度）和0℃下饲养的日本蟹C. japonica和厚壳贻贝M. coruscus。 mg L ^-1纳米TiO ₂浓度条件。研究结果表明，变暖和纳米TiO ₂扰乱了螃蟹的ATP产生、消化反应和身体化学成分，导致肠道菌群功能障碍。 值得注意的是，纳米TiO ₂对螃蟹的消化酶和肠道菌群的影响比单独变暖更强。然而，变暖和纳米TiO ₂的同时存在，特别是在直接暴露（DE）条件下，通常会加剧纳米TiO ₂的负面影响。这项研究为了解纳米 TiO ₂和高温对海蟹消化反应的影响提供了宝贵的见解。