摘要：We cultured five species of rotifers (Brachionus angularis, B. calyciflorus, B. patulus, Euchlanis dilatata, and Lepadella patella) under different algal concentrations (Chlorella vulgaris) for a period of 10 to 15 days, and we derived the rate of population growth per day (r) for each rotifer species. Using a regression between food concentration and the r for each rotifer species, we calculated the minimal food level required to maintain a zero growth rate (threshold food concentration). For all the tested species, there was a direct and positive relationship between food concentration and peak population density. The highest peak density (738 ind. mL -l ) was achieved by L. patella at 0.4X10 6 cells mL -1 . At this food density, B. calyciflorus was only able to reach about 10 ind. mL -1 . The highest r value (0.46 d -1 ) was observed for L. patella at 0.4X10 6 cells mL -1 ; at this food concentration, B. calyciflorus and E. dilatata had much lower r values (0.21 and 0.23 d -1 , respectively). On a dry weight basis, L. patella had the lowest threshold food concentration (0.0023 mg C t -1 d -1 ), while B. calyciflorus needed much higher levels (2.04 mg C L -1 d -1 ). Larger-bodied taxa had higher threshold food concentrations than the smaller-bodied rotifers.
