Sugarcane, one of the world’s major crops, is used to produce sucrose and biofuel. Before harvesting, sugarcane is burned to facilitate manual cutting, generating ashes that may reach water bodies and cause the death of aquatic organisms. While studies have addressed the lethal effects of sugarcane ashes (SCA) on different fishes, little is known about the effects of sublethal SCA concentration on aquatic organisms. In this study, we evaluated the behaviour of a piscivorous (Hoplerythrinus unitaeniatus) and an invertivorous (Moenkhausia forestii) fish species, after a short-term (24 h) exposure to a sublethal concentration of SCA (0.8 g L⁻¹). We hypothesized that the outcomes of predator–prey interaction would change when the players are subjected to sublethal SCA concentration. Our findings revealed that neither the behaviours of predator and prey fish species nor the outcome of their interactions was changed by the exposure to sublethal SCA concentrations, suggesting that their behavioural traits were not particularly sensitive to SCA. However, we emphasize that (i) other predatory and anti-predator behavioural traits could be affected by SCA even at under 0.8 g L⁻¹ concentration and (ii) higher concentrations of SCA and/or long-term exposure may trigger profound changes in the behaviour of predator and prey fish species. Our findings are worrisome because there are new public policies to expand sugarcane production in Brazil, with the possibility of continuing burning sugarcane crops across the country. This will increase the input of SCA into aquatic systems, generating more prominent and pervasive negative impacts than those evaluated in this study.

甘蔗是世界主要农作物之一，用于生产蔗糖和生物燃料。甘蔗在收获前被焚烧以方便人工切割，产生的灰烬可能会到达水体并导致水生生物死亡。虽然研究已经解决了甘蔗灰 (SCA) 对不同鱼类的致死影响，但对亚致死 SCA 浓度对水生生物的影响知之甚少。在这项研究中，我们评估了食鱼( Hoplerythrinus unitaeniatus ) 和倒食 ( Moenkhausia forestii ) 鱼类在短期 (24 小时) 暴露于亚致死浓度的 SCA (0.8 g L ^-1）。我们假设当玩家受到亚致死 SCA 浓度的影响时，捕食者-猎物相互作用的结果会发生变化。我们的研究结果表明，暴露于亚致死 SCA 浓度下，捕食者和猎物鱼类的行为及其相互作用的结果都没有改变，这表明它们的行为特征对 SCA 并不是特别敏感。然而，我们强调 (i) 即使在 0.8 g L ^-1以下，SCA 也会影响其他捕食性和反捕食者行为特征(ii) 较高浓度的 SCA 和/或长期接触可能会引发捕食者和猎物鱼类行为的深刻变化。我们的调查结果令人担忧，因为巴西出台了扩大甘蔗生产的新公共政策，并有可能在全国范围内继续燃烧甘蔗作物。这将增加 SCA 对水生系统的输入，产生比本研究中评估的那些更显着和普遍的负面影响。