Dietary Spirulina Ameliorates Arsenic-Induced Toxicity in Nile Tilapia, Oreochromis niloticus

Arsenic (As) contamination in aquaculture systems poses a serious threat to fish health, food safety and sustainable production, yet effective nutritional strategies to mitigate its toxicity remain limited. This study evaluates the protective role of dietary spirulina against As-induced physiological and biochemical disturbances in Nile tilapia (Oreochromis niloticus). In this study, the Nile tilapia O. niloticus (0.65 ± 0.04 g) were exposed to As with or without spirulina, representing control (no spirulina and As); T1, (spirulina 0 g/kg and As 5 mg/kg); T2 (spirulina 0 g/kg and As 10 mg/kg); T3 (20 g/kg of spirulina and As 5 mg/kg); and T4 (20 g/kg of spirulina and As 10 mg/kg) for 56 days. At the completion of the feeding trial, fish were analysed for growth, feed performance and haematological traits. A significant decrease (p < 0.05) in weight gain (WG) and specific growth rate (SGR) was observed with increasing dietary As levels when compared to the control group. However, dietary spirulina improved the negative effects on fish growth. Similarly, lower feed utilization observed in the fish fed non-spirulina As supplemented diet in comparison to spirulina supplemented diet. Haemoglobin (Hb) content significantly (p < 0.05) lowered with the increase of As level in non-spirulina supplemented fish, however dietary spirulina improved the Hb level. On the other hand, opposite trend noticed in term of blood glucose levels. Moreover, dietary spirulina supplementation significantly lowered the As accumulation in fish muscle in comparison to non-spirulina supplemented group. The results of this study indicate that spirulina has a notable capacity to counteract the toxic effects of As in Nile tilapia.