Evaluation of two probiotics used during farm production of white shrimp Litopenaeus vannamei (Crustacea: Decapoda).

This study examined the effects of Bacillus licheniformis strain CIGBC-232, isolated from the gut of shrimp Litopenaeus vannamei and having antagonistic activity against Vibrio harveyi, on the immunity and larval quality of L. vannamei at various ontogenetic stages, in two separate experiments: (1) PL2 to PL17 exposed to the strain CIGBC-232 under laboratory conditions (2) zoea I to PL8 exposed to the strain CIGBC-232 and EPICIN 3W probiotics under farming conditions. The first experiment showed that phenoloxidase, peroxidase and superoxide dismutase activities were improved in animals grown with CIGBC-232 compared to the untreated control. In tests, the resistance to osmotic stress was also enhanced. During the second experiment, animals treated with CIGBC-232 exhibited significant ( P < 0.05) increases in phenoloxidase activity (30-40% higher in zoea I- II, mysis II- III and PL 2-7) and in the respiratory burst (30% higher from PL 2 to 7) as compared to those animals that received EPICIN 3W. There was no significant difference in the lectins and agglutinins (except in PL1, 6 and 7), in peroxidase and superoxide dismutase activities, in the resistance to osmotic stress, nor in the survival rate among treatments. CIGBC-232 treatment was able to reduce, the level of presumptive Vibrio spp. with respect to EPICIN 3W treatment in the tank water as well as in animals. At the end of both experiments, the growth of shrimp, i.e. weight and length was increased by CIGBC-232 treatment. This study showed the probiotic effect of CIGBC-232, which appeared to have a better probiotic performance than EPICIN 3W treatment. [ABSTRACT FROM AUTHOR]