Entrance of different levels of Bacillus subtilis and Lactobacillus plantarum probiotics separately in shrimp tank and their effects on larvae quality, growth index of Macrobrachioum rosenbergii and water quality

TThis study examined the possibility of improving the quality of Macrbrachium rosenbergii larvae and water quality using different levels of Bacillus subtilis and Lactobacillus plantarum probiotics separately in semi-enclosed shrimp culture system. For the research conduction, 24000 newly hatched larvae of the giant freshwater shrimp obtained from the Ghasre-shirin hatchery center and were stocked in the experimental tanks by 40 larvae/liter density for one month. This experiment was designed in 25 liter tanks with four treatments; the first treatment (control without probiotic), the second treatment (106cfu/g), the third treatment (107cfu/g) and the fourth treatment (108cfu/g) in triplicates (for each of probiotics were designed separately). The results showed that with increasing the concentration of Bacillus subtilis probiotic up to 107 bacteria per gram, the parameters including DO, ORP, TDS, LSI and LCI have significantly an increase trend and at higher concentrations these parameters are reduced. It also showed that the bacterial density of Bacillus subtilis can be represented as a limiting factor and in higher concentration of 107 has negative results on larval growth and water quality. In L. plantarum probiotic treatment, increasing the number of bacteria, affected larvae quality and water quality, In the treatment of 108, the best probiotic performance of L. plantarum was recorded. In general, according to the results, the concentrations of 107 and 108 for B. subtilis and L. plantarum probiotics are respectively recommended in the hatchery centers of the giant freshwater shrimp.