GROWTH, SIZE AND REPRODUCTION IN DAPHNIA (CRUSTACEA: CLADOCERA)*

摘要: 1Factors influencing the growth of Daphnia are summarized; it is shown that lack oxygen inhibits magna. 2Synchronization egg laying by females in samples from natural populations has been found on several occasions. 3The pre-adult studied rearing 207 specimens belonging to eight species standard conditions. The greatest increment does not always occur at end adolescent instar; may pre-adolescent instar or more rarely even earlier. 4Initial size influences which maturity reached; as initial increases animals tend become mature earlier instars. 5In single a direct correlation between and number eggs carried their brood pouches. This applies certainother Cladocera (excluding subfamily Chydorinae). 6Synchronous fluctuations parthenogenetic pouches have population D. magna. 7Factors young analysed. Within following factors operative: relation mother, age inherited racial clonal characteristics, available food temperature. 8The ephippial magna varies with female producing them. be bigger smaller than eggs. 9The thirty-three measured. larger produce slightly maternal those species. 10A can assimilate enough material during each dry weight least equal her body after laid. 11The diminishes 16 25 per cent embryonic development.