Effects of environmental factors on the feeding of Apocyclops royi
环境因素对短角异剑水蚤摄食的影响

To develop the intensive culture technology of Apocyclops royi, the filtering rate (F) and grazing rate (G) on Dunalilla salina OUC38 under different water temperature, illumination, pH, cell density and gender, and the selective feeding on three common diet microalgae of D. salina OUC38, Isochrysis galbana and Chlorella sp., were assessed by single-factor experiments. As a result, there are no significant difference between filtering rates and grazing rates of A. royi at 3 test temperatures (20, 25 and 30 °C), and the highest filtering rates and grazing rates are (0.049±0.014) mL ind.-1h-1 and (1.393±0.369)×104 cell ind.-1h-1 at 25°C, respectively. The filtering rate and grazing rate increase with the increase of illumination intensity. The highest filtering rates and grazing rates are (0.053±0.012) mL ind.-1h-1 and (1.295±0.303)×104 cell ind-1h-1 respectively under 9 800 lx illumination. Both the filtering rate and grazing rate at pH 9.0 are significantly higher than those under pH 7.0, 8.0 and 10.0. The grazing rate rises with increasing cell density of the D. salina, while the filtering rate increases to the highest level and declines thereafter. There is sexual dimorphism in filtering rate and grazing rate of A. royi. The filtering rate and grazing rate of female are both 16% higher than those of male. Among the 3 tested diet microalgae, I. galbana is the most favorite diet of A. royi.