Effects on development and microbial community of shrimp Litopenaeus vannamei larvae with probiotics treatment

Shrimp production is the second ranked of the most-traded production in these decades and the whiteleg shrimp Litopenaeus vannamei is the sixth most cultured species. Probiotics are alternative strategy for the promotion of growth and prevention of diseases in aquaculture. To confirm the effects of the probiotics on development and microbial community of L. vannamei larvae during different development stages, five kinds of probiotics (10⁸ ~ 10⁹ CFU/g) were added into the rearing environment of shrimp larvae, and the effects of probiotics on bacterial community and water quality, larval growth and immune index were determined from nauplius larval stage to post larval stage. Results suggested that probiotics treated groups showed larger survival rate than the control groups from Z1 stage to P5 stage. Lactobacillus could improve the larvae's survival ability, especially in the larval stages M2, M3, P1, P5 stage. It was confirmed that probiotics could promote the growth and development of shrimp larvae and prevent the incomplete molting in their growing process, particularly for EM-treated group. Results suggested that all the probiotics-treated groups had shown significant decreasing trend in the quantity of vibrios, except for the SA-treated group. And different probiotics could inhibit vibrios during different life periods. Among these probiotics, LA, EM and PB had shown the best effects, including improving survival rate of the larvae, promoting the larval metamorphosis, reducing the quantity of vibrios and NH₄-N and NO₂-N levels, and increasing bacterial diversity.