Four distinct colonies were isolated from the intestine of Blue morph (Maylandia lombardoi) through serial dilution, pour plate, spread plate and streak plate method. The isolated colonies were identified by using biochemical and enzyme (Amylase, Cellulase, Lipase and Protease) productivity tests. The isolated bacteria such as Bacillus sp., (BM1), Enterobacter sp., (BM 2), Escherichia sp., (BM3) and Pseudomonas sp., (BM4) were mass multiplied in nutrient broth. Antibacterial activity of intestinal bacteria of Blue morph was carried out with the help of selective media along with commercial antibiotic Ampicillin. Based on higher enzyme productivity  and antibacterial activity two bacteria  were sequenced and the identified as BMI(Lactobacillus casei)  and BM2 (Lactobacillus acidophilus).Five different feeds having different concentration of bacteria such as Feed I (Control)(without bacteria), Feed II (1ml of Lactobacillus casei ), Feed III (1ml each of Lactobacillus casei  and Lactobacillus acidophilus ), Feed IV(1 ml each of  Lactobacillus casei,  Lactobacillus acidophilus Bacillus sp., and Escherichia sp.,) and Feed V (1ml each  of Lactobacillus casei,  Lactobacillus acidophilus Escherichia sp., and Pseudomonas sp.,)were prepared by using fish meal, groundnut oil cake, wheat flour and tapioca flour. Feed utilization parameters of Blue morph were estimated after a period of 21 days. Based on the antibacterial test the Lactobacillus acidophilus (BM2) has higher inhibition. The feed consumption, feed conversion ratio, feed conversion efficiency, growth, percentage growth, relative growth rate, assimilation, metabolism, gross growth efficiency, and net growth efficiency was higher in feed IV.