Background: Microplastics pollution in aquatic ecosystems is a growing concern due to its potential adverse effects on aquatic organisms. Ingestion by fish and other organisms microplastics can cause poisoning, diseases and fatalities.&nbsp; 
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Methods: Oreochromis niloticus fingerlings were exposed to various microplastic concentrations: T0 as the control and T1, T2 and T3 groups were treated with 100, 150 and 200 mg/L of microplastics respectively for 28 days. Growth performance was assessed by tracking weight gain, absolute weight gain, total length and specific growth rate weekly while hematological parameters were evaluated through complete blood count (CBC) test. 
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Result: The study found that exposure to high concentrations (T3) of nylon microplastics significantly decreased the weight and length rates of Oreochromis niloticus. The condition factor and specific growth rate also showed notable changes however, survival probability remained unaffected across all groups. CBC test revealed that red blood cell count, platelet count, hemoglobin concentration, hematocrit level, MCV and MCH decreased in higher levels of nylon microplastics exposure. In contrast, white blood cells, monocytes, eosinophils, lymphocytes and MCHC levels increased. While low concentrations showed no significant variations. The research highlighted the ecological risk of nylon microplastic pollution to freshwater fish particularly Oreochromis niloticus. 
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Effects of Microplastics (Nylon) on the Growth and Blood Profile of Oreochromis niloticus