Abstract: To evaluate the effects of light color on the growth of juvenile Plectropomus leopardus and its biochemical indices of serum, using different breeding tanks in a small circulating water aquaculture system, five lighting conditions, namely white light, red light, yellow light, green light and dark were set for the cultivation experiment for 120 days, in which the size of fish was initially 19.67±1.26 cm with the body weight of 92.92±4.05 g. The results indicate that light color had significant effects on the growth and survival of juvenile P. leopardus. The green light group had the highest survival rate and body weight, and the white light group had the highest hepatosomatic index (HSI). The white light group had lower contents of blood sugar, blood lipids and proteins, while it had higher alanine aminotransferase (ALT), aminotransferase (AST), and lactate dehydrogenase (LDH) than the other four groups, especially the LDH from the white light group was significantly higher than those in the red light and green light groups. Juvenile fish in the white light group had the higher creatinine (CREA) and blood urea nitrogen (BUN) than those in other four groups (P<0.05). Except Mg²⁺, the contents of inorganic ions, including Ca²⁺, P³⁺, Na⁺, K⁺ had no significant difference among the five light groups. In conclusion, green light was the best for the growth and survival of P. leopardus.

Key words: peanut, biomass, nutrient accumulation, ecological adaptability, comprehensive eva-luation.