Remedial and toxic effects of lead exposure in Catla catla juveniles: Assessment of growth, carcass, blood profile and tissue metal analysis.
Abstract
In recent years, waterborne heavy metal (HM) contamination is a major concern in aquaculture systems due to its detrimental effects on fish health. Therefore, the development of effective dietary strategies to alleviate HM-induced toxicity is imperative for ensuring the sustainability of aquaculture production. The present study investigated the efficacy of dietary garlic powder (GP) in mitigating the adverse effects of lead (Pb) on growth indices, hematological parameters, digestive enzyme activity, carcass composition, and tissue health of Catla catla (Thaila). A total of 270 fish were allocated to 18 tanks in triplicate (n=15/tank). Five dietary treatments were formulated containing 0, 5, 10, 15, or 20 g kg-1 GP. The experimental groups were as follows: G1, negative control with no GP supplementation and no Pb exposure; G2, positive control with no GP supplementation and exposure to 1 mg L-1 Pb; and G3-G5, supplemented with 5, 10, or 20 g kg-1 GP, respectively, with exposure to 1 mg L-1 Pb. The experimental duration was sixty days. Results demonstrated that waterborne Pb toxicity had significant (P<0.05) negative impacts on C. catla in terms of growth, body composition, hematology, intestinal enzymes and oxidative stress biomarkers. Pb concentrations increased significantly in the gills, spleen, liver, and kidneys of Pb-exposed fish relative to control. In contrast, GP supplementation significantly (P<0.05) reversed the harmful effects of Pb and improved the growth, blood profile, carcass characteristics, digestive enzyme activities and oxidative status of fish, with the most pronounced effects at 5 g kg-1 diet. In conclusion, the dietary GP incorporation into the diets of C. catla effectively improved fish health and mitigated Pb toxicity. These findings revealed that garlic can be used as a natural feed additive to improve fish resilience against HM stress in aquatic environments.