Recently, the toxic effects of tralopyril, as a new antifouling biocide, on aquatic organisms have aroused widespread attention about the potential toxicity. However, the mechanism of tralopyril on marine mollusks has not been elaborated clearly. In this study, the histological, biochemical and molecular impacts of tralopyril on adult Crassostrea gigas were investigated. The results indicated that the 96 h LC50 of tralopyril to adult Crassostrea gigas was 911 μg/L. After exposure to tralopyril (0, 40, 80 and 160 μg/L) for 6 days, the mantle mucus secretion coverage ratio of Crassostrea gigas was increased with a dose-dependent pattern. Catalase (CAT) activity was significantly increased, amylase (AMS) activity, acid phosphatase (ACP) activity and calcium ion (Ca²⁺) concentration significantly decreased. Meanwhile, integrated biomarker responses (IBR) index suggested that higher concentrations of tralopyril caused severer damage to Crassostrea gigas. In addition, the mRNA expression levels of biomineralization related genes in the mantle were significantly upregulated. Collectively, this study firstly revealed the histological, biochemical and molecular impacts of tralopyril exposure on adult Crassostrea gigas, which provided new insights for understanding the toxicity of tralopyril in marine mollusks.

近来，作为一种新型防污杀菌剂，曲虫嘧啶对水生生物的毒性作用引起了人们对其潜在毒性的广泛关注。然而，tralopyril对海洋软体动物的作用机制尚未阐明。在这项研究中，研究了曲虫嘧啶对成年牡蛎的组织学、生化和分子影响。结果表明，曲嘧啶对巨牡蛎成虫的96 h LC50为911 μg/L。暴露于 tralopyril (0, 40, 80 and 160 μg/L) 6 d后,牡蛎的地幔粘液分泌覆盖率以剂量依赖性模式增加。过氧化氢酶（CAT）活性显着升高，淀粉酶（AMS）活性、酸性磷酸酶（ACP）活性和钙离子（Ca ²⁺）浓度显着降低。同时，综合生物标志物反应（IBR）指数表明，较高浓度的曲菌灵对巨牡蛎造成的损害更严重。此外，地幔中生物矿化相关基因的mRNA表达水平显着上调。总体而言，本研究首次揭示了tralopyril暴露对成年牡蛎的组织学、生化和分子影响，为了解tralopyril对海洋软体动物的毒性提供了新的见解。