Response mechanisms of Litopenaeus vannamei to nitrite exposure at different dissolved oxygen levels

The tolerance of shrimp to nitrite toxicity can be influenced by a number of factors. The influences of dissolved oxygen (DO) levels on Litopenaeus vannamei under nitrite exposure would be well worth exploring. Therefore, L. vannamei were exposed to nitrite for 72 h at the low DO (LDO, 2.38 to 2.85 mg/L), moderate DO (MDO, 6.39 to 6.75 mg/L), and high DO (HDO, 11.68 to 13.37 mg/L) levels. Nitrite exposure at the LDO and HDO levels were detrimental to the metabolism of lipid, amino acid, and carbohydrate, and the signal transduction of JAK/STAT, PI3K/Akt, and mTOR signaling pathway. In conclusion, nitrite exposure at the LDO and HDO levels exacerbated stress and apoptosis, reduced metabolic levels, impeded signal transduction, and accelerated mortality in L. vannamei. This study preliminarily revealed the mechanism of response to nitrite exposure at different DO levels in L. vannamei. Theoretical support was provided for the mitigation of nitrite toxicity to L. vannamei at different DO levels.