Impact of Acute Hypoxia Stress on the Antioxidant Capacity and Tissue Damage of <em>Penaeus monodon</em>

Abstract

This experiment was conducted to examine the effects of acute hypoxia stress on <em>Penaeus monodon</em>, specifically focusing on its antioxidant capacity and tissue damage. The study aimed to understand how acute hypoxia stress influences these physiological parameters in <em>P. monodon</em>. Hepatopancreas and gill tissues were sampled at three distinct dissolved oxygen (DO) levels: a normoxic condition of 6 mg·L⁻¹, a hypoxic condition of 2 mg·L⁻¹, and an acute hypoxic condition of 1 mg·L⁻¹. Tissue collections were performed after exposure periods of 2 hours and 4 hours, respectively, to assess the effects of varying oxygen concentrations over time. The activities of immune enzymes (ACP, AKP) and antioxidant enzymes (T-AOC, T-SOD, MDA) were measured, and the hepatopancreas and gill tissues were examined through sectioning. The results showed that under hypoxic stress, the activity level of the experimental shrimp increased, the movement of the eye stalk was rapid, and the antennae and abdomen were significantly curved. AKP activity initially increased in response to stress but decreased over prolonged hypoxia exposure. ACP activity decreased with prolonged hypoxia but showed some recovery over time. T-AOC and MDA activities decreased with prolonged hypoxia exposure. T-SOD activity showed an increasing trend but decreased under excessive hypoxia. Different degrees of damage were observed in the hepatopancreas and gill tissues under hypoxia stress. The study indicates that hypoxia stress affects the activity of immune and antioxidant enzymes in <em>P. monodon</em>, causing tissue damage to the hepatopancreas and gills. These findings help elucidate the response mechanism of <em>P. monodon</em> to hypoxia stress and provide a reference for the healthy aquaculture of this species.