Elevated temperature disrupts the mucosal structure and induces an immune response in the intestine of whiteleg shrimp Litopenaeus vannamei (Boone, 1931) (Decapoda: Dendrobranchiata: Penaeidae)

Abstract

We investigated the effects of thermal stress on the mucosal structure and the immune response in the intestine of the whiteleg shrimp Litopenaeus vannamei (Boone, 1931). Examination of histological sections showed that thermal stress damaged the epithelium of the intestinal mucosa. The experimental shrimp were acclimated for one week before thermal stress. In response to thermal stress, there was an increase in the oxidative stress parameters, including the activity of ·O2- -generation capacity and the contents of lipid peroxidation and malondialdehyde, while antioxidant activities (superoxide dismutase, catalase, and glutathione peroxidase) and the expressions of the heat shock protein 70 and thioredoxin genes showed significant variations (P < 0.05). Immune activities (acid phosphatase and alkaline phosphatase) were decreased after 24–72 h of thermal stress, and the metabolic activity of lactate dehydrogenase and the expression of the hypoxia-inducible factor 1α gene were higher than those of the control group. These results revealed that thermal stress impaired the intestinal barrier of the shrimp by damaging the mucosal structure, inducing oxidative stress, and compromising the immune and metabolic status.