Effect of water administrated probiotics on striped catfish (Pangasianodon hypophthalmus) exposed to sumithion

Sumithion, a synthetic organophosphate, is commonly applied in aquaculture to eliminate tiger bugs before the stocking of fish larvae. However, its toxic effects often outweigh its intended benefits, posing significant risks to fish health. The present study investigated the capability of probiotics to mitigate the adverse effects of sumithion in striped catfish ( Pangasianodon hypophthalmus ). Fish with an average body weight of 10.82 g were distributed into four treatment groups: T1 (Control), T2 (sumithion 0.6 mg/L), T3 (probiotics 1 mL/L), and T4 (sumithion + probiotics), each with three replicates over a 42-day period. Growth performance indicators such as final body weight (FBW), weight gain (WG), specific growth rate (SGR%), and feed conversion ratio (FCR) were all adversely affected in the sumithion-only group (T2). In contrast, the combined treatment group (T4) showed marked improvement compared to T2, with growth parameters closely approaching those observed in the control group. Intestinal histology revealed pronounced deformities in T2, which were substantially alleviated in T4 with probiotic supplementation. Hemato-biochemical analysis showed significantly (p < 0.05) improved hemoglobin and glucose levels in the combined treatment group (T4) compared to T2. Additionally, erythrocytic cellular (teardrop, twin, elongated, fusion) and nuclear (micronuclei, nuclear bridges, nuclear buds, karyopyknosis) abnormalities were most frequent in T2 but were considerably reduced in probiotic-treated group. Gene expression analysis revealed that probiotic supplementation (T4) enhanced the expression of immune-related genes (IL-1β, IFN-α2) and antioxidant genes (SOD, CAT), indicating an immunomodulatory and antioxidative effect under pesticide-induced stress. These results suggest that probiotics can alleviate the physiological, histological, and molecular damage caused by sumithion, thereby promoting fish health and supporting sustainable aquaculture in environments impacted pesticide exposure. • Chronic exposure to sumithion produced toxicological effects in striped catfish • Sumithion affected growth, blood, oxidative and immune stress markers • Inclusion of probiotics significantly repaired physiological impairments induced by sumithion