The interaction of light intensity and pH on the hatching performance of Artemia franciscana in laboratory condition

Given the importance of Artemia as the most live feed used in the aquaculture industry, the interaction between light intensity and pH was investigated in two levels of light 1000 and 2000 lux, and three levels of pH 8, 9 and 10 on the percentage of hatching, percentage of umbrella stage and percentage of unhatched cyst on Artemia franciscana. To determine the percentage of hatching, percentage of umbrella stage and percentage of the unhatched cyst, samples were taken from each replicate after 48 hours of the beginning of the incubation. According to the results, there was no interaction between the two factors of light intensity and pH (P = 0.383). There was no significant difference between two light intensities (p = 0.305). However, the highest hatching rate was observed at 2000 lux light intensity. The difference was significant between three pH treatments in the percentage of hatching and percentage of the unhatched cyst (P < 0.001). So that, the highest and lowest hatching rates were observed at pH 9 (73.03 ± 6.98 %) and pH 10 (47.67 ± 2.58 %), respectively. In order, the highest and lowest of umbrella stage were observed at pH 8 (5.96 ± 0.87 %) and pH 9 (2.31 ± 0.58 %). Also, the highest and lowest of unhatched cyst were observed at pH 8 (33.05 ± 3.67 %) and pH 9 (24.65 ± 3.56 %), respectively. According to the results of the present study, it can be suggested that for achieve the maximum hatching rate of Artemia franciscana cyst, it could be used water with a pH 9 and the light intensity 2000 lux