Growth and enzymatic profile of the Pacific white shrimp fed with Porphyridium cruentum extract

Abstract

The study was developed to evaluate the influence of diet supplementation of a polysaccharide extract from the microalgae Porphyridium cruentum, on weight gain, digestive enzyme activity, and Litopenaeus vannamei juvenile survival. The polysaccharide crude extract from microalgae P. cruentum was added at different concentrations (0, 0.5, 1, 1.5, and 2.0%) in a commercial diet and provided to juvenile L. vannamei (6.6 ± 0.2 g). The shrimps (n =2,000) were fed ad libitum for 30 days in circular tanks with 12 m² of bottom area (100 shrimp tank^-1) and environmental variables (temperature, salinity, dissolved oxygen, photoperiod and level of total ammonia) were controlled. The supplemented diet with 1% crude extract was responsible for the biggest weight gain (7.28 g) in 30 days. The shrimp body muscle centesimal composition and survival were not affected by the polysaccharide extract supplementation. It was observed a shift in the activity of digestive enzymes from the hepato-pancreas to the anterior midgut and mid midgut portions in shrimps with diet supplemented with 1% polysaccharide extract, which may have contributed to a better digestive efficiency. The results indicate that dietary supplementation with crude extract of P. cruentum polysaccharides in a range between 1 and 1.5% increases weight gain and enhances the activity of digestive enzymes in L. vannamei juveniles.