Effect of periodic light intensity change on the molting frequency and growth of Litopenaeus vannamei

• Growth of Litopenaeus vannamei in five light intensity treatments was tested.
• Suitable periodic fluctuation of light intensity could promote growth.
• High FCEd was one reason for better growth.
• Higher energy allocation for growth was another reason for better growth.
• Periodic light fluctuation was more suitable in the industrialized shrimp culture.

Five light intensity treatments (60 lx, “CL”; 600 lx changed to 60 lx, “FL1”; 1500 lx changed to 60 lx, “FL2”; 3000 lx changed to 60 lx, “FL3”; 6000 lx changed to 60 lx, “FL4”) were tested to determine the growth of Litopenaeus vannamei under periodic light intensity change conditions. After 45-day experiment, shrimp in FL2 treatment showed the best weight gain (WG) and specific growth rate (SGRd), which might have been caused by high food conversion efficiency (FCEd), lowest energy allocation for respiration and excretion, and highest energy allocation for growth. The molting frequency in FL4 treatment was the lowest and significantly lower than those in other treatments, but the growth was not the worst. These results suggest that periodic light intensity fluctuation from 1500 lx to 60 lx could promote growth of L. vannamei which could be used as a pattern of regulation of light intensity in the commercial shrimp culture.