Temperature affects physiological processes in organisms and the toxicity of chemicals. The widespread industrial use of ZnO causes contamination in aquatic ecosystems. This study aimed to investigate the chronic toxicity of ZnO at different temperatures using Daphnia magna as a model organism. The chronic toxicity of five different concentrations of ZnO was assessed at 23 °C and 28 °C. The results showed that higher concentrations of ZnO inhibited growth, production of first clutch eggs and juvenile accumulation at both 23 °C and 28 °C. Growth rate, numbers of first clutch eggs and juvenile accumulation were lower at 28 °C than at 23 °C. We also observed the levels of malondialdehyde (MDA) and superoxide dismutase (SOD) activity. At higher concentrations of ZnO, oxidative stress was induced leading to increase MDA level and decrease SOD activity at 28 °C. These findings indicated that high temperature and high concentration of ZnO inhibited the activity of enzymatic proteins. Nonetheless, among all treatments, the accumulation of zinc in D. magna was not significantly different. Our results suggested that both ZnO and higher temperature induced oxidative stress in D. magna. As a result, MDA concentration increased, SOD activity changed and the growth and reproduction of D. magna was adversely affected.

温度会影响生物体的生理过程和化学物质的毒性。ZnO在工业上的广泛使用引起了水生生态系统的污染。这项研究旨在研究使用水蚤（Daphnia magna）在不同温度下ZnO的慢性毒性。作为模型生物。在23°C和28°C下评估了五种不同浓度的ZnO的慢性毒性。结果表明，较高的ZnO浓度在23°C和28°C时均会抑制生长，第一窝卵的产生和幼虫的积累。28°C时的生长速率，第一窝卵的数量和幼虫的积累低于23°C。我们还观察到了丙二醛（MDA）和超氧化物歧化酶（SOD）活性的水平。在较高的ZnO浓度下，在28°C时会诱发氧化应激，从而导致MDA含量升高和SOD活性降低。这些发现表明高温和高浓度的ZnO抑制了酶蛋白的活性。尽管如此，所有的处理中，锌的积累大型溞没有明显的不同。我们的研究结果表明，ZnO和较高的温度都会引起D. magna的氧化应激。结果，MDA浓度增加，SOD活性改变，并且对D. magna的生长和繁殖产生不利影响。