FACTORS INHIBITING GROWTH OF THE ROTIFER BRACHIONUS-PLICATILIS IN HIGH-DENSITY CULTIVATION BY FEEDING CONDENSED CHLORELLA

In order to investigate the factors inhibiting the growth of rotifer ( S-type) in high density cultivation, a series of experiments were cond ucted, cultivating rotifer in 30 l and 1 kl vessels by feeding condens ed Chlorella. Although there was no difference in the maximum populati on of rotifer in the culture experiments at different temperatures of 24, 28, and 32-degrees-C, the growth rate increased as the culture tem perature increased. In the cultivation system supplied with air, the m aximum rotifer population did not exceed 4,000-5,000 individuals/ml be cause oxygen levels were restricted due to the accumulation of undisso ciated ammonia. Feeding oxygen gas to the rotifer culture system enabl ed high density cultivation with a population of 20,000 individuals/ml . In such an oxygen-rich culture system, the concentration of undissoc iated ammonia is considered to be the main factor inhibiting the growt h of rotifer.