Influences of environmental factors on waste discharging by Japanese carpet shell Ruditapes philippinarum

Rapid discharge of wastes by Japanese carpet shell Ruditapes philippinarum was determined at various water temperature,salinity,pH and illumination to search for quick cleaning technology.The results showed that quicker discharge of wastes was found in the animals maintained at 15-20 ℃ than at other temperature,89.59% of the wastes eliminated in 4 hour treatment.The animals showed rapid discharge of wastes at a salinity of 25-30,with removal rate of 88.4% 4 hours after treatment.There was more rapid discharge of wastes by Japanese carpet shell in darkness than in natural light,the percentage of the discharged waste being 85.92% 4 hours after treatment.The quicker discharge of waste was observed in the low alkaline water at pH 7-8 than in the other conditions,with removal rate of 87.99% 4 hours after treatment.It is concluded that good purification can be achieved at water temperature of 15-20 ℃,salinity 20-30 and pH 7-8 in darkness.