Lacticaseibacillus casei in Diet of Juvenile Convict Cichlid Fish (Amatitlania nigrofasciata): Evaluating Growth Performance, Digestive Enzyme Activities, Immune Responses, and Stress Resistance

In this study, growth performance, body composition, digestive enzymes activity, mucosal and immunological parameters, cultivable bacterial populations, and stress resistance were investigated in juvenile convict cichlid fish ( Amatitlania nigrofasciata ) that received a dietary supplement containing 0 (control), 5 × 10 6 (LC1), 5 × 10 7 (LC2), and 5 × 10 8 CFU g −1 diet (LC3) Lacticaseibacillus casei PB-LC39. Two hundred and forty fish (2.44 ± 0.04 g) were assigned to twelve experimental aquariums and feed ad libitum three times a day for 8 weeks. After final sampling, final body weight, percentage of weight gain (WG %), specific growth rate (SGR), food conversion ratio (FCR), and protein content of whole‐body composition were significantly higher ( P