The experimental result showed that 7 days after treating with toxicants, the toxiceffect revealed, based on changes of Daphnia magna body-length, is same as that of 21 days chronic toxicity test.

• 试验结果表明,毒物对大型溞的毒性作用,在试验后的7d内已可从其体长的变化显示出来,并与21d的慢性毒性试验结果等效。