First, the toxicity tests cannot be done with Artemia eggs, but with the adult crustacean. Second, at least the medium used to be tested should have a salinity somewhere near that of seawater, other wise the animal would die just because due to intolerence to differential salinity.

Thank you sir. I referred papers relevant to this and there were some deviation in the methodology adopted...i just  have confusion in standardizing the volume of the assay components. I am attaching few references herewith.

Read through the papers. They are using Artemia naupli for the tests, but the salinity is not mentioned. Nevertheless the animal at that stage can also be used, in which case the reporting has to be done accordingly. There are cases wherein bioassay tests are done using phytoplankton also. The practical point is to get a steady supply of the test animals/plants for various tests to be conducted. Probably Artemia came in handy in that case.

The general bioassay tests done for industrial effluents is by using a 2 inch fry of fish per one litre of the effluent (diluted as required).

There is one company selling Artemia cysts in Tamil Nadu. You can Google out the source for cycts.