Effect of sulfated polysaccharides extracted from the red alga Halymenia pseudofloresia on survival of the shrimp Litopenaeus vannamei

Abstract

The aim of this work was to evaluate the effect of sulfated polysaccharides (SP) extracted from the red marine alga Halymenia pseudofloresia on the survival rate of Pacific white shrimp, Litopenaeus vannamei, submitted to stress conditions. The SP were extracted through enzymatic digestion from marine algae collected in Praia de Fleixeiras-CE. The experiment consisted of three treatments with different doses of SP (0.5 and 1.5 μg.L-1 and 1.0 mg.L-1) fed through immersion baths and a control without SP, each one with three replications. The experiment had a 20 days (20-day) duration, which the first 15 days were used to immersion baths application, and the last 5 days were used to stress induction by culture water exchange suppression. Doses application was done twice a day after water exchange and before the animals’ feeding. After stress induction shrimp mortality of 1.0 mg.L-1 treatment was significantly lower than that of control and 0.5 μg.L-1 treatment. At the end of the experiment 1.0 mg.L-1 treatment shrimps were also submitted to a SP extraction, and the DEAE-celulose column chromatography of these SP resulted in a similar profile of that obtained from the marine alga. The results showed that 1.0 mg.L-1 application of SPs from H. pseudofloresia was capable to reduce mortality of L. vannamei shrimps submitted to stress conditions.