Effect of different photoperiods of artificial green LED lighting in a biofloc system on growth and oxidative stress in Litopenaeus vannamei

We assessed the impact of various green light photoperiods from LED lamps on water quality, microorganism community, antioxidant capacity, lipid peroxidation, and growth performance in Pacific white shrimp Litopenaeus vannamei in a BFT system. The study was conducted indoors in 150-L tanks using shrimp with an initial weight of 0.48 g at a stocking density of 500 shrimp m−3 for 61 days. The experiment was designed with four treatments with four replicates each, with different green light photoperiods: 1) 16 h L/8 h D, 2) 12 h L/12 h D (control), 3) 8 h L/16 h D and 4) 4 h L/20 h D. No significant differences were found in water quality parameters following trial completion (p > 0.05). However, there were significant differences in the bacterial abundance of coccoids, free filamentous, attached filamentous, vibrios, and bacilli (p < 0.05) and in protozoa including flagellates, ciliates, rotifers, nematodes, and amebae (p < 0.05). There were also significant differences in lipid peroxidation, with lower lipid peroxidation in the 12 h L/12 h D, 8 h L/16 h D, and 4 h L/20 h D treatments and higher antioxidant capacity in the hepatopancreas and muscle in the 8 h L/16 h D treatment (p < 0.05). Shrimp from the 8 h L/16 h D treatment showed a higher final weight than those from the 12 h L/12 h D control treatment (p < 0.05). Thus, a photoperiod of 8 h of light and 16 h of darkness with green LED light is suggested for rearing L. vannamei in biofloc systems.