Effect of sulfated polysaccharides from red marine algae on Litopenaeus vannamei post-larvae, submitted to the saline stress test

Abstract

The experiment was carried out to evaluate the effect of the administration of sulfate polysaccharides (SP) extracted from marine red algae Champia feldmannii, Halymenia pseudoforesia e Gracilaria birdiae, on the survival of Litopenaeus vannamei shrimp postlarvae (PL’s), submitted to the saline stress test, used to verify the shrimp quality. The SP were administered in concentrations 0.0 mg.L-1 (Control); 1.0 mg.L-1and 2.0 mg.L-1 (C. feldmannii); 2.0 mg.L-1 and 4.0 mg.L-1 (H. pseudoforesia) e 2.0 mg.L-1and 4.0 mg.L-1 (G. birdiae) and the stress test carried out after the administration period. Therefore, 100 individuals from each treatment, acclimated to salinity 30, were transferred to recipients containing freshwater, where they stay for one hour, and then restored again to original condition and stay there for more 30 minutes. The procedure was repeated four times for each treatment, being recorded the number of survivors at the end of the trials. Survival average values were submitted to the ANOVA and Tukey Test (α=0.05). Higher survival was observed for G. birdiae 2.0 mg.L-1 treatment (94.36%), witch was significantly superior than the lowest values recorded on Control (76.75%) and C. feldmannii 1.0 mg.L-1and 2.0 mg.L-1 (75.37% e 74.94%) treatment. The results show that G. birdiae (2.0 mg.L-1) SP ascribed a greater resistance to L. vannamei PL’s, submitted to saline stress, suggesting a possible protector effect of this compound, which should be investigated in subsequent studies.