RESUMEN
The present study was performed to evaluate the toxic effects of imidacloprid (IMI) insecticide on the growth performance, oxidative status, and immune response of Nile tilapia, Oreochromis niloticus (L.), and the protective role of dietary supplementation of spirulina, Arthrospira platensis, (SP). Fish (20.2 ± 0.5 g) were assigned to bifactorial design (2 IMI levels x 3 SP levels) to represent 6 treatments in triplicates. Spirulina was incorporated in diets at levels of 0.0 (control), 20, and 40 g/kg diet. Under each SP level, fish were exposed to 0.0 or 0.05 µg IMI/L. Fish in each treatment were fed on the corresponding diets up to apparent satiation thrice a day for 8 weeks. Two-way ANOVA revealed a significant decline in growth indices, hepatic superoxide dismutase, catalase, and glutathione peroxidase activities in the IMI-exposed fish. Contrariwise, serum alanine and aspartate aminotransferases, alkaline phosphatase, urea, creatinine, and malondialdehyde levels were markedly higher along with significant reductions of the reduced glutathione, nitric oxide as well as lysozyme values in the IMI-exposed fish group. The dietary supplementation of SP showed stimulating effects on the growth performance, haemato-biochemical, oxidants/antioxidants, and immune biomarkers of Nile tilapia with optimum level of 20 g SP/kg diet. Interestingly, the dietary supplementation of SP to Nile tilapia attenuated the above-mentioned variables with improving the growth performance, haemato-biochemical, oxidative stress, and immunity biomarkers. Therefore, the dietary supplementation of 20 g SP /kg diet could be a valuable candidate as a natural antioxidant for ameliorating the IMI toxicity in Nile tilapia.