Evaluation of the productive and physiological responses of Litopenaeus vannamei infected with WSSV and fed diets enriched with Dunaliella sp.

• Shrimp were fed a diet enriched in Dunaliella sp.
• Survival of WSSV-infected shrimp on the enriched diet was increased.
• Blood metabolites of shrimp on the enriched diet increased by day 3.

An experimental investigation was performed to evaluate the productive and physiological responses of Litopenaeus vannamei that were infected with WSSV and fed diets enriched with Dunaliella sp., which had a high β-carotene content induced by nitrogen reduction in the culture medium. A basal diet containing 35% crude protein and experimental diets T1 and T2, which included 1% and 2% microalgae meal, respectively, were evaluated. Positive (infected juveniles) and negative (non-infected) controls were also evaluated. Survival was significantly higher (80%) in the two treatment groups compared to the positive control group (56%). In the negative control group, survival was 100%. Some variation was recorded for hemolymph metabolites among treatments and at distinct times post-infection; although the tendencies were not clear, some metabolites (glucose and triglycerides) appeared to decrease on the last days of the trial, probably due to their use as energy for the shrimp to thrive despite the infection. The results of the study suggest a positive effect of the dietary inclusion of Dunaliella meal on shrimp survival and an unclear effect on hemolymph metabolites.

Mortality of Litopenaeus vannamei after 144 h post inoculation and hemolymph metabolites in controls and treatments (glucose and protein). C1: negative control, C2: positive control, T1: 1% Dunaliella sp. on diet and T2: 2% Dunaliella sp. on diet.Figure optionsDownload as PowerPoint slide