STUDIES ON THE MARINE CLADOCERA OF CHINA Ⅲ. REPRODUCTION

Studies are made on the reproduction of two common marine Cladocera (Penilia avirostris, Evadne ter-gestina) of China with emphasis on the fertility of parthenogenetic females (P♀). A positive correlation exists between the fertility and the size of the same species; but no such correlation is found between the fertility and the size of different species. The fertility is, on the whole, higher in summer and is related to the seasonal fluctuation of population density, both attaining their maximum period in summer; but the former appears about half a month earlier than the latter, A brief account is given of the sexual reproduction, including the respective size and the seasonal variation of sexual individuals (S♀,♂) together with a note on the sex-ratio and the characteristics of resting egg.

STUDIES ON THE MARINE CLADOCERA OF CHINA Ⅲ. REPRODUCTION

Studies are made on the reproduction of two common marine Cladocera (Penilia avirostris,Evadne ter-gestina) of China with emphasis on the fertility of parthenogenetic females (P♀).A positive correlation exists between the fertility and the size of the same species; but no such correlation is found between the fertility and the size of different species.The fertility is,on the whole,higher in summer and is related to the seasonal fluctuation of population density,both attaining their maximum period in summer; but the former appears about half a month earlier than the latter,A brief account is given of the sexual reproduction,including the respective size and the seasonal variation of sexual individuals (S♀,♂) together with a note on the sex-ratio and the characteristics of resting egg.