Arsenic (As) can co-occur with zirconium dioxide nanoparticles (ZrO₂ NPs) in aquatic environments, but their combined influence along the aquatic food chain is barely explored. This study constructed water flea Daphnia magna – zebrafish Danio rerio to evaluate the impact of ZrO₂ NPs on the accumulation, trophic transfer, transformation, and detoxification of arsenate (As(V)). The zebrafish were fed D. magna exposed to As(V), ZrO₂ NPs, or As(V) + ZrO₂ NPs for 20 d. Results demonstrated that ZrO₂ NPs significantly facilitated total As and As(V) sorption in D. magna and in tissues of zebrafish. ZrO₂ NPs enhanced the transformation of inorganic arsenic (iAs) to monomethylated acid (MMA), while decreased synthesis of arsenobetaine (AsB) in tissues, leading to iAs increased. Co-exposed As(V) and ZrO₂ NPs facilitated upregulation of absorption-related genes (aqp7) and As biotransformation-related genes (gst, gss), and detoxification and oxidative stress-related genes (mt2, cat, sod1 and sod2). Therefore, genetic expression coupling with biotransformation for the first time demonstrated that As(V) combined with ZrO₂ NPs led to increased harm to D. magna and zebrafish and amplified the ecological risks of As(V) along the aquatic food chain. Attention should be paid to the combined toxicity of As(V) and ZrO₂ NPs in aquatic environment.

砷 (As) 可以与水生环境中的二氧化锆纳米粒子 (ZrO ₂ NPs) 共存，但它们对水生食物链的综合影响却鲜有研究。本研究构建了水蚤Daphnia magna – 斑马鱼Danio rerio，以评估 ZrO ₂ NPs 对砷酸盐 (As(V)) 的积累、营养转移、转化和解毒的影响。斑马鱼被喂食暴露于 As(V)、ZrO ₂ NPs 或 As(V) + ZrO _{2 NPs 的}D. magna 20 天。结果表明，ZrO ₂ NPs 显着促进了D. magna和斑马鱼组织中的总 As 和 As(V) 吸附。氧化锆₂ NPs 增强了无机砷 (iAs) 向单甲基化酸 (MMA) 的转化，同时减少了组织中砷甜菜碱 (AsB) 的合成，导致 iAs 增加。共暴露的 As(V) 和 ZrO ₂ NPs 促进了吸收相关基因 ( aqp7 ) 和 As 生物转化相关基因 ( gst , gss ) 以及解毒和氧化应激相关基因 ( mt2 , cat , sod1和sod2 )的上调. 因此，基因表达与生物转化的结合首次证明了As(V)与ZrO ₂ NPs的结合会增加对D. magna的危害。和斑马鱼，并放大了水生食物链中 As(V) 的生态风险。应注意As(V)和ZrO ₂ NPs在水生环境中的联合毒性。