Dietary effects of microplastics on the physiological and biochemical profiles of keystone secondary producers Oithona dissimilis (Lindberg,1941)

Abstract The present study was carried out on the impacts about microplastic ingestion on the physiological responses and nutritional profiles of marine copepod Oithona dissimilis . The survival rate (93.33%) was higher on the 15 th day in control. The highest nauplii production achieved in control O. dissimilis (21.89 ±0.89 nauplii/female), whereas the production of nauplii was found lowest in treatment groups (12.56±0.89 nauplii/female). The nauplius development (N1-N6) duration was less (4.3 days) in control, while longest duration depicts the MPs exposed copepods ranges were 5.2 days in 0.1 μm; 5.9 days in 0.5 μm and 6.6 days in 2.0 μm respectively. The protein content was high (63.07%) in control copepods, whereas in MPs exposed copepods ranges varied between 43.20%, 46.5% and 51.50%. The carbohydrate content in MPs ingested copepods varied between 10.33%, 8.93%, and 9.57%. The maximum lipid content was achieved in control (13.33%) when compared to MPs exposed copepods illustrates the minimum lipid content varied between 8.97% (0.1μm size) followed by 10.7% (0.5μm size) and 11.21% (2.0 μm size). The statistical results that depict the amino acids and fatty acids contents of control (microalgae fed copepods) have found the maximum positive significance (p<0.05) with different sizes (0.1µm, 0.5µm & 2µm) of microplastics exposed copepods.