Midultraviolet (UV‐B) sensitivity of Acartia clausii Giesbrecht (Copepoda)1

The sensitivity of all life stages of laboratory‐cultured Acartia clausii to various fluences of UV‐B radiation was evaluated. Organisms were irradiated on a rotating turntable beneath FS40 sunlamps and “deluxe white” fluorescent lamps. Copepods were randomly assigned to treatments utilizing a randomized complete block design. Least‐squares regression analysis was performed between surviving fraction and fluence for all treatments administered to each age group and also between the offspring:survivor ratio and fluence for treatments administered to the oldest age group, which was composed of equal numbers of males and females. Results indicated an inverse relationship between surviving fraction and UV‐B exposure. Reproductive capability of the surviving organisms was also negatively affected.