Abstract:
To investigate the effects of bixafen on aquatic invertebrates, this study utilized
Daphnia magna to conduct 48-hour and 21-day exposure tests, systematically investigating the acute and chronic toxicities of bixafen on
D. magna. The acute toxicity test showed that the 48 h EC
50 value of bixafen was 0.964 mg/L, indicating a high level of toxicity. The chronic toxicity test revealed that long-term exposure to bixafen could significantly delay the first brood time of
D. magna, and reduce the first brood size, total number of broods, and total brood size. The molting rate and body length of
D. magna were also inhibited. In addition, the intrinsic growth rate of
D. magna significantly decreased after 21 d exposure to bixafen. The 21-d lowest observed effect concentration (LOEC) and no observed effect concentration (NOEC) of bixafen to
D. magna were 0.08 mg/L and 0.04 mg/L, respectively. In conclusion, bixafen exhibits high acute toxicity to
D. magna, and long-term exposure to bixafen at low concentrations can significantly inhibit the reproduction and growth of
D. magna, posing a high risk to
D. magna populations. Our results enrich the aquatic toxicology information of bixafen, and also provide a more comprehensive and accurate scientific basis for risk assessment of bixafen to aquatic ecosystems.