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.
Plastic fragments < 5 mm, known as microplastics (MPs), are ubiquitously present in the marine environment. Research on MPs pollution has gradually shifted from field investigations to laboratory studies. With the rapid growth of plastic consumption and the prevalence of aquaculture products, studies on marine MPs have focused on key marine species, such as mollusks. This review summarizes the recent knowledge including 77 important relevant literatures (from 2010 to 2021) on MPs contamination in mollusks with the objectives of (1) elucidating the current status of MPs pollution levels in mollusks, (2) highlighting the main methods and techniques for separation, extraction, and identification of MPs in soft tissues of bivalves and (3) presenting the current research progress and future directions. The review visually presents some of the important results in graphic form, which shows that the most common polymer plastics in bivalves are polypropylene, polystyrene, and polyethylene, and the shapes were mainly fiber and threadiness, mollusks are more likely to feed smaller MPs, most of the MPs in bivalves are less than 500 μm, and the abundance of MPs in seawater and the abundance of MPs in mollusks have a positive relationship, etc. This review will provide a comprehensive reference for studies of microplastics in marine organisms and the ecological pollution, and also has scientific guiding significance in the research method.