Effects of T-2 toxin on growth, immune function and hepatopancreas microstructure of shrimp (Litopenaeus vannamei)

• Exposure of shrimp to T-2 toxin significantly decreased specific growth rate and weight gain.
• T-2 toxin damaged the hepatopancreas in a dose-responsive manner.
• Hemolymph phenoloxidase activity could be used as a sensitive indicator of immune damage in shrimp exposed to T-2 toxin.

T-2 toxin (T-2) is a trichothecene-A-type mycotoxin produced by the fungus Fusarium spp., which can contaminate animal feed. It is toxic to many living cells especially the hepatocytes and bone marrow cells. The effects of dietary T-2 on growth, biochemical and immunity parameters, and histopathological changes in the hepatopancreas of white shrimp (Litopenaeus vannamei) were studied. Shrimp with an initial body weight of 3.5 ± 0.5 g were fed five diets (n = 50/group) containing 0, 0.5, 1.2, 2.4, or 4.8 mg kg− 1 T-2. Dietary exposure to T-2 significantly decreased shrimp growth rate and specific growth rate (P < 0.5), but not the fat content, compared with the control group. Exposure to T-2 damaged the hepatopancreas microstructure in a dose-dependent manner and this may have contributed to a lower hemolymph albumin concentration and lower phenoloxidase activity. Total hemocyte counts and activity of hemolymph glutamic-pyruvic transaminase > glutamic-oxaloacetic transaminase and alkaline phosphatase enzymes increased initially in a dose-dependent manner but declined thereafter. This study showed that T-2 is a multi-organ toxin with effects on the hemolymph, immune system, and hepatopancreas of shrimp. Collectively, these effects may have contributed to the inhibition of growth and decreased survival rate leading to a lower yield and quality of shrimp meat with resultant economic loss.Statement of relevanceIt is proposed that hemolymph phenoloxidase enzyme activity could be used as a cheap non-specific biomarker for initial screening of shrimp exposed to even low T-2 toxin concentrations, instead of more expensive LC-MS/MS T-2 analysis — although a dose response was not evident at high exposure concentrations.