东海原甲藻（Prorocentrum donghaiense）对中华哲水蚤（Calanus sinicus）摄食和消化酶活性的影响

Effect of Prorocentrum donghaiense on feeding and digestive enzyme activity of marine planktonic copepod Calanus sinicus, a key species of Yellow Sea and East China Sea, was studied using single and mixed culture methods under controlled laboratory conditions. The results show that: (1) C. sinicus takes some P. donghaiense with the maximum ingestion rate (IR) of 930 cells/(ind•h), and the IR is closely related with the microalga density. Differently, the clearance rate (CR) decreases monotonically with microalga density increasing during the whole experiment. (2) The IRs of C. sinicus on Isochrysis galbana and P. donghaiense in mixed cultures are lower than those of two microalga species in single culture. (3) The digestive enzyme activity of C. sinicus changes with microalga species and density. The activity of laminarinase is higher than those of maltase and cellobiase, and cellobiase has little lower activity than those of other two. The result also shows that the microalga species affects the digestive enzyme activity. C. sinicus fed with P. donghaiense showed relatively higher digestive enzyme activity than those fed with I. galbana (P＜0.05).