Using clonal culture and life-table techniques

we studied the effect of UV-B radiation whose experimental dose were 0.00

0.24

0.48

0.72

0.96 and 1.20 kJ /m

2

on experimental population dynamics of the rotifer Brachionus plicatilis feeding on algae Chlorella sp.with a density of 1.0×10

6

cells/ml at（23±1）℃.The main results were as follows:（1） The survival time of the rotifer Brachionus plicatilis was significantly shortened by UV-B radiation treatment（p

<

0.05） and the longest survival time with 390 h occurred in the control

while the shortest with 300 h appeared in the highest UV-B radiation treatment(1.20 kJ/m

2

);（2） The fecundity of the rotifer was notably affected by UV-B radiation（p

<

0.05） and was promoted by the lower UV-B radiation treatment(0.24

0.48 and 0.72 kJ/m

2

) but inhibited by the higher UV-B radiation treatment(0.96 and 1.20 kJ/m

2

);（3） The life expectancy was also obviously affected by UV-B radiation（p

<

0.05）.The highest Life expectancy was recorded in the control and became shorter with the dose increas of the UV-B radiation

indicating that the life expectancy of the rotifer Brachionus plicatilis can be used as an ideal index for the enhancement of UV-B radiation.