Effect of adding probiotics into the rearing tanks of grass carp (Ctenopharyngodon idella) for the exploitation of Artemia urmiana, Artemia fransiscana and Artemia parthenogenetica Nauplii

Bacillus spp. are Gram-positive spore-forming bacteria used commercially as probiotics in the larviculture of fish. Bacillus spp. can act positively on cultured organisms by enhancing their survival and growth, stimulating their digestive and immune systems, and improving water quality. In this present study, grass carp larvae were fed on Artemia urmiana, Artemia fransiscana and Artemia parthenogenetica nauplii. In probiotic trials, the combination of Bacillus circulans and Bacillus licheniformis was also added to rearing tanks of grass carp at 1×106 CFU/L. Final body weight, specific growth rate, thermal growth coefficient, daily growth coefficient and relative gain rate were all affected by the addition of probiotic Bacillus spp. (P<0.05). The greatest improvements in growth parameters were obtained in the group fed A. parthenogenetica plus probiotic bacteria, while the group fed A. urmiana plus probiotic bacteria had significantly (P<0.05) lower growth parameters compared with the other treatments. Thus, the grass carp larvae performed best when fed with A. parthenogenetica nauplii and the probiotic bacteria.