Like 80 mmol/dm~3 K~(+), K~(+)-free or Mg~(2+)-free seawater would produce evidence of toxicity. The mechanisms of ionic control of settlement and metamorphosis in the Styela canopus Savigny larvae were discussed.

• 另外；人工海水中缺乏K+或Ca2+或K+浓度达80mmol/dm3 都会对冠瘤海鞘幼体产生毒害作用.