Short communication: Acute toxicity of hydrogen peroxide in juvenile white shrimp Litopenaeus vannamei reared in biofloc technology systems

Biofloc technology (BFT) has been used to rear white shrimp, Litopenaeus vannamei. In this culturing system, the absence of aeration causes a rapid drop in dissolved oxygen levels, and hydrogen peroxide (H2O2) can be used as an emergency source of oxygen. This study aimed to determine the lethal concentration and safe level of H2O2 applied as a source of oxygen for juvenile white shrimp L. vannamei in a BFT system. Juveniles (1.39 ± 0.37 g) were exposed for 2 h to different concentrations of H2O2 [29 (100), 58 (200), 116 (400), 174 (600), 232 (800), 290 (1,000) and 348 (1,200) μL H2O2/L (ppm H2O2-29 %/L)] in addition to a control group without addition of H2O2, and the survival rates were monitored for 96 h. The LC50 values and 95 % confidence intervals at 24, 48, 72 and 96 h were 235.5 (207–268), 199.1 (172–229), 171.1 (146–198) and 143.3 (120–170) μL H2O2/L, respectively. The safe level was 14.3 μL H2O2/L, and the highest concentration with survival rates similar to the control group (NOAEC) was 29 μL H2O2/L. In these concentrations, H2O2 can be used as a safe source of oxygen for L. vannamei reared in BFT systems.