RESUMO
The present study was conducted to assess the establishment and effect of probiotic bacteria such as Bacillus coagulans, Bacillus mesentericus, and Bifidobacterium infantis in the gut of freshwater ornamental fish Puntius conchonius. Postlarvae of 60 days old Puntius conchonius divided in four experimental groups each with three replicates. T1, T2 and T3 groups were fed with Bacillus coagulans, Bacillus mesentericus and Bifidobacterium infantis enriched copepod Thermocyclops decipiens respectively. T0 was the control group (without probiotic treated T.decipiens). The experiment was conducted for 45 days. The initial gut analysis of fish showed significant level of pathogenic bacteria in the gut of fish (p<0.05). Total plate count of initial gut analysis of fish larvae were enumerated as 1.2 x 104 CFU ml-1. The bacteriological study indicated that final gut microflora of post-larvae have decreased level of pathogens. Total plate count of T1, T2, T3 and T0 were reported to be as 1.08x104, 1.06x104, 1.27x104 and 2.1x105 CFU ml -1, respectively. Three experimental groups (T1, T2 and T3) were significantly different from control group (T0) (p<0.05). At the end of the experiment, establishment of probiotics were examined. One week after probiotics administration, gut analysis of fish larvae showed, poor spore formation of Bacillus coagulans (2.3x10³ CFU ml -1), when compared to B. mesentericus (3.2±0.03x10³ CFU ml -1) and Bifidobacterium infantis (3.1x10³ CFU ml -1). The results from the study suggest that the probiotic bacteria significantly established in gut of P. conchonius and significant effects on the pathogenic gut inhabitants of the fish.