The Effects of Shrimp Gut Probiotic Bacteria on the Shrimp Larvae (Penaeus Chinensis)

The survival rates of shrimp larvae in different stage are higher than those of control groups when probiotic bacteria strains X4B-1 and X1B-1 which are isolated from gut of adult shrimp are added into the little volume rearing sea water of shrimp larvae. The effects of probiotic bacteria are evaluated by challenge test (pathogenic bacteria Z3G2 isolated from disease shrimp larvae in the hatchery of Jimo town) and low salinity stress resistance tests on shrimp larvae, the survival rate and lengths of the shrimp larvae in the experiment are determined. Results indicate that 1. The survival rate, ability of resistant to low salinity, lengths of the delivered shrimp larvae are improved after the strains of probiotic bacteria, X4B-1 or X1B-1, are added into the rearing sea water of hatchery. 2. The addition of the probiotic bacteria could not influence the change of the bacteria number, NH3-N and COD value in the rearing sea water. 3. The probiotic bacteria used in the experiment have many enzymes such as Lipase, Amylase, Gelatinase and Lecithinase. These enzymes may help the probiotic bacteria to digest the food components fed to shrimp larvae and increase the digestive efficiency of post larvae. This may be one of the reasons why these probiotic bacteria are beneficial to the shrimp larvae.