Affiliations: Institute of Environmental Sciences, Zhejiang
University, Hangzhou 310029, China | Institute of Feed Science, Zhejiang University,
Hangzhou 310029, China
Abstract: The acute and chronic toxic effects of bifenthrin on Daphnia magna
were studied. The results showed that 24 h-EC_{50}, 48
h-LC_{50} and 96 h-LC_{50} of bifenthrin
on D. magna were 3.24, 12.40 and 1.40 μg/L respectively. And the LOEC and
NOEC of bifenthrin were 0.02 and 0.004 μg/L respectively. The recovery test
of bifenthrin on Daphnia magna was presented. Daphnia magna
(F_0 generation) were exposed during 21 d to different
bifenthrin concentrations. Offspring (animals from the first and third brood:
F_1(1st) and F_1(3rd), respectively) were
transferred to a free pesticide medium during a 21-day recovery period. In this
recovery study, survival, growth, reproduction (mean total young per female,
onset of reproduction and number broods per female) and the intrinsic rate of
natural increase (r) were assessed as parameters. Reproduction such as number
of young per female as well as length was still reduced in
F_1(1st) generation daphnids from parentals
(F_0) exposed to the bifenthrin. However
F_1(3rd) individuals from parentals exposed to pesticide
concentrations were able to restore reproduction when a recovery period of 21 d
was allowed, but the length of F_1(3rd) from parentals
exposed to the 0.5 and 0.75 μg/L bifenthrin concentration was still
significantly effected (P<0.05).
Keywords: bifenthrin, Daphnia magna, parental generation (F[TeX:] _0), F[TeX:] _1(1st) and F[TeX:] _1(3rd), recovery test, toxic test
