Ammonia-N accumulation in the rice-crab co-culture system may have negative effects on the health of juvenile Eriocheir sinensis. In this study, physiological, transcriptomic, and metabolomic analyses were performed to explore the toxic responses in the hepatopancreas of juvenile E. sinensis exposed to 0, 0.75, and 2.99 mmol/L total ammonia-N for 24 h. We observed that the content of most amino acids and glycogen was significantly decreased after ammonia exposure. Acid phosphatase and alkaline phosphatase activities showed marginally increased trends after low ammonia exposure. Transcriptomic analysis indicated that immune defense, detoxification, and metabolic pathways were altered. Metabolomic analysis revealed that ammonia exposure affected energy metabolism and nucleotide metabolism. The combination of transcriptomic and metabolomic analyses revealed that the tricarboxylic acid cycle and amino acid consumption were enhanced for additional energy supply to cope with ammonia stress. Ammonia stress activated the immune defense system in juvenile E. sinensis. Moreover, the upregulation of detoxification genes and the acceleration of glycogen degradation for glucose supply are important adaptive mechanisms in response to high ammonia stress. Notably, ammonia stress may affect the nervous system of juvenile E. sinensis. Thus, our data provide a better understanding of the defensive mechanisms of E. sinensis against ammonia toxicity.

稻蟹共养系统中氨氮积累可能对中华绒螯蟹幼体的健康产生负面影响。在这项研究中，进行了生理学、转录组学和代谢组学分析，以探索幼年E. sinensis肝胰腺的毒性反应暴露于 0、0.75 和 2.99 mmol/L 总氨氮 24 小时。我们观察到氨暴露后大多数氨基酸和糖原的含量显着降低。酸性磷酸酶和碱性磷酸酶活性在低氨暴露后显示出略有增加的趋势。转录组学分析表明免疫防御、解毒和代谢途径发生了改变。代谢组学分析表明，氨暴露影响能量代谢和核苷酸代谢。转录组学和代谢组学分析的结合表明，三羧酸循环和氨基酸消耗得到增强，以提供额外的能量供应以应对氨胁迫。氨胁迫激活了幼年E. sinensis的免疫防御系统。此外，解毒基因的上调和葡萄糖供应的糖原降解加速是响应高氨胁迫的重要适应机制。值得注意的是，氨应力可能影响少年的神经系统E.吸虫。因此，我们的数据可以更好地理解E. sinensis对氨毒性的防御机制。