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.

Growth rate, soluble protein content, osmotic stress and digestive enzyme activity were studied in early Litopenaeus schmitti postlarvae under different feeding regimens, by partially or completely replacing Artemia nauplii with Moina micrura. Growth was significantly higher in the postlarvae fed with a mixture of M. micrura, Artemia nauplii and algae (0.030 mg dry weight (dw) larva )1 day )1 , 17.4 ± 2.1% day )1 ), together with the postlarvae fed on Artemia nauplii and algae (0.027 mg dw larva )1 day )1 , 18.3 ± 1.9% day )1 ). Complete replacement of Artemia nauplii by M. micrura produced the lowest growth rate (0.018 mg dw larva )1 day )1 , 14.3 ± 1.6% day )1 ) and induced the highest protease and a-amylase activities and lower soluble protein contents. No significant difference among the treatments could be detected in postlarval resistance to osmotic stress. Based on the growth results, soluble protein content, enzymatic activity and osmotic stress resistance, we determined that the partial replacement of Artemia nauplii by M. micrura did not affect the growth, the soluble protein content and the nutritional state in the postlarvae of L. schmitti. To our knowledge, this is the first reported use of M. micrura as feed for early postlarvae of L. schmitti. KEY WORDS

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Electroporation of Litopenaeus schmitti embryos was used to transfer the pE300tiGH15 plasmid that contains the tilapia growth hormone gene (tiGH) complexed with a nuclear localization signal peptide into the zygotes. The gene construct was detected in 35 (36%) of the 98 larvae screened by PCR and Southern blot analyses. Western blot analyses revealed that 34% of the screened larvae expressed a single tiGH-specific band with the expected molecular mass (23.1 kDa). The development index and larval length indicated a significant growth enhancement from day 3 on after electroporation, with an average of 32% of the growth enhancement. To our knowledge, this is the first report on gene transfer enhanced growth in crustaceans.

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