通気量の違いがプロアレスProales similis の水槽内分布状況に及ぼす影響

Abstract

The change in distribution of the proalid rotifer Proales similis was determined during a 5-hour experiment under no aeration in order to confirm the behavioral specificity in a 500-L polyethylene tank. The effect of the amount of aeration on the scattering of P. similis in the tank was also analyzed. The aeration volume was set at six levels from 10 to 500 mL/min, and dispersion of P. similis was investigated at each level. The results showed that P. similis sank more easily without aeration. Under the condition of 20 mL/min aeration, a slight stirring effect by the aeration was evident at 10-30 cm in depth. The stirring effect became more remarkable as the aeration volume increased, resulting in an almost uniform density of P. similis throughout the rearing tanks with 200 and 500 mL/min of aeration.