Impact of UV-B Radiation on the Fecundity of the Copepod 'Acartia clausii'

摘要

It has recently been demonstrated that acute midultraviolet irradiation (UV-B, 290 to 320 nm) of the marine copepod Acartia clausii results in reduced survival and fecundity. In the present study, immature late copepodites were separated by sex and exposed to three UV-B exposure levels (0, 25, and 50 effective DNA Jsq. m). The irradiated copepods were then reared to sexual maturity and adult virgin survivors were mated according to prior exposure, supplying 7 different types of mating crosses (MOFO, MOF25, M25FO, M25F25, MOF50, M50FO, M50F50). Six replications of each cross were maintained for the duration of an experiment. Two experiments are documented. There was a significant effect of UV-B radiation on the survival of the parents as well as a reduction in the number of eggs and the number of living nauplii produced. For each experiment, 30 nauplii from each type of cross were separated, repeated to maturity and counted, providing information on the survival capability of non-irradiated off-spring from the seven different mating types. Previous exposure of parental stock did not significantly affect the survival, and development to maturity, of these nauplii 15 d after separation.