8월 5일 The effect of solar UVA and UVB on subarctic Daphnia 김철민

The effect of solar UVA and UVB on subarctic Daphnia pulicaria in its natural habitat I. D. Zellmer Abstract The effect of solar radiation, especially the ultraviolet regime (UVA and UVB), has been examined on Daphnia pulicaria (Forbes) in a subarctic lake. Daphnia were exposed to four radiation regimes: total radiation, exclusion of UVB, exclusion of UVA and UVB and dark controls. Exposure lasted 2?4 days in 2 depths (8 cm and 24 cm). In the subsurface (8 cm) exposure survival was significantly increased when UVB or UVB and UVA were excluded. In addition, the percentage of egg carrying Daphnia and the number of live offspring increased significantly when UVB was excluded. In 24 cm depth, an increase of survival was noticeable only in some of the experiments. Differences in reproduction due to different radiation regimes, too, were not significant. The results demonstrate that not only UVB, but UVA also may have a significant effect on Daphnia in their natural habitat.