Combined effect of light intensity and salinity on hatchability of Artemia cystsbased onresponse surface methodology

Using central composite design and response surface methodology, we explored the combined effect of light intensity and salinity on hatchability of Artemia cystsas well asdetermined the optimum experimental combination. The results show that the linear and quadratic effects of light intensity and salinity had very significant effect on hatchability (P0.01) under experimental conditions; no significant interaction was found between light intensity and salinity on hatchability (P0.05). The hatchability increasedthen decreased as light intensity or salinity increased. High fitting degree of hatchability to the quadratic regression equation of independent variables (light intensity and salinity) indicated its possibility of prediction. The optimum conditions for germination were light intensity of 2 134.02 lx and salinity of 31.57 gL-1, under which the hatchability reached 29.86% and the reliability peaked to 0.983.Moreover, since the verification result of the optimum conditions accorded with the predicted value,it is suggested that the hatchability of Artemia cystscan be improved underoptimum light intensity and salinity.