Effects of temperature and food on population growth and reproduction of rotifer, Brachionus plicatilis

Dong Jing; Yu Yehui; Zhao Yingying; Wei Kanyun; Gao Haiyu; Li Lin

Abstract：Effects of temperature and food concentration on population growth and reproduction of rotifer, Brachionus plicatilis were studied in growth three temperatures (20℃,25℃ and 30℃) and different food concentrations (1 × 106cells/mL,10 × 106cells/mL and 20 × 106cells/mL). The culture was lasted for 10d. The results showed that there were very significant in the effects of tempera-ture and food concentration on the population density, population growth rate and egg ratio. The maximum population density decreased after the first increase with temperature and food concentra-tion increase. When the food concentration was 10×106cells/mL at 25℃, the maximum population den-sity was 74.39 ± 1.81ind/mL, which was significantly higher than that in the other groups(P<0.05). With the increase of temperature, the time of maximum peak rotifer population density also showed a gradual emergence of forward trends, the largest population growth rate increased with the in-crease of temperature and food concentration. When the food concentration was 20 × 106cells/mL at 30℃, the largest population growth rate was 0.70±0.013 which significantly higher than the other groups(P<0.05). At the same temperature, the maximum egg ratio increased with the increase of con-centration in food. When the food concentration was 20 × 106cells/mL, the maximum egg ratio was 56.43±1.07%, which was significantly higher than in the other groups(P<0.05). In conclusion, tem-perature and food concentration had significantly effects on the population growth and the repro-duction of rotifer, Brachionus plicatilis. It is suggested that the optimum food concentration was 10×106cells/mL and the temperature was at 25℃.