have shown that different wavelengths affect the enzymatic activity in Palaemon serratus, thus affecting digestibility, assimilation and the growth of shrimp. In our study,the FCEd of shrimps in B treatment was the lowest and significantly lower than those in G, BY and BG treatments. However, the FCEd of shrimps experiencing the blue light in BY and BG treatments was higher. That may be caused by the light color fluctuation