Study Of Standard Methods Of Acute Toxicity Tests Of Artemia Nauplii

Artemia nauplii are more and more used in the acute toxicity tests as examined biology. Because of the different experimental methods,the results were imprecise and incomparable.We choose 5 strains of Artemia which were GSL,SG,AB,BH and BY to research the acute toxicity tests' method of Artemia nauplii.The LC₅₀-Hg²⁺ of different strains of Artemia nauplii were GSL 28.79rag/L,SG 6.11mg/L,AB 10.96rag/L,BH 12.64mg/L,BY 16.44mg/L in turn.Artemia cysts of GSL do not only have good quality,high production, but also are accessible and widely used.The stable creature trait is the most important factor of Artemia nauplii which are hatched from the salt cysts.Therefore,GSL Artemia were chosen as experimental materials of the follow-up experiments.We ascertained the standard method which was obtaining the synchronous hatchedArtemia nauplii in the same age,based on the research of Artemia cysts' HR and the molting time of Artemia naupli. The tolerances of instarâ… and instarâ…¡Artemia to Hg²⁺ were different,the LC₅₀ were 24.48mg/L and 4.58mg/L;The LC₅₀-Hg²⁺ of I₀,I₅,I₁₁,I₁₆ were 22.79mg/L,19.26mg/L, 17.56mg/L,5.57mg/L in turn.It means that the tolerances of Artemia in different instars and ages were significantly different.And the LC₅₀-Hg²⁺ of junior and Artemia adult were 61.35mg/L and 44.9mg/L respectively.In order to normalize the experiment methods,we selected Artemia nauplii which were synchronous and just hatched(I₀) to proceed the acute toxicity tests.On the base of the standard methods,we determined LC₅₀ of different kinds of toxin. The LC₅₀ of different kinds of heavy metal ions were Cd²⁺ 665.75rag/L,Hg²⁺ 24.48mg/L, Pb²⁺ 309.34mg/L,Cr³⁺ 78.82rag/L,Cu²⁺ 66.87mg/L in turn.The sequence of toxicity was Hg²⁺＞Cu²⁺＞Cr³⁺＞Pb²⁺＞Cd²⁺;The LC₅₀-NH₄⁺ was 6.64×10³mg/L.Different organic toxin have different effects on the death rate of Artemia nauplii.The LC₅₀ were CH₂O 1.59×10³mg/L,SDS 20.93mg/L,diesel oil 658.11mg/L,phoxim 234.54mg/L in turn.According to studying on Artemia cysts' HR and the molting time of Artemia naupli, we found the standard method which was obtaining the synchronous hatched instarâ… Artemia for the first time.The importance of fixing the strain,instar and the age to the acute toxicity tests was made clearly.We set up the standard method of the acute toxicity tests of Artemia nauplii initially,and then proceeded the acute toxicity tests of different toxin systematically.