EFFECT OF TEMPERATURE ON THE DEVELOPMENT, GROWTH AND EGG PRODUCTION IN MOINA AFFINIS (CLADOCERA, MOINIDAE)
Huang Xiangfei(Institute of Hydrobiology, Academia Sinica)
The embryonic and postembryonic development of the Cladoceran Moina affinis at 30℃ and 20℃ has been studied in the laboratory.The duration of embryonic and postembryonic development is inversely proportional to the temperature. Embryonic development lasts 18—20 hrs at 30℃ and 42—48 hrs at 20℃. The total life span is 15.7 days at 30℃ and 33.3 days at 20℃.There are only two pre-adult instars followed by thirteen adult instars at 30℃ whereas at 20℃ there are three pre-adult instars followed by twelve adult instars.The rate of egg production on a cumulative basis varies with temperature. It is found that at 30℃ Moina affinis has a higher rate of egg production (a=1.1811) than at 20℃ (a=0.9643)The data on the life cycle of Moina affinis has been compared with other five cladoceran species.