This study investigated the effects of cadmium (Cd), microplastics (MPs), and pectin (Pec) supplementation on biochemical, oxidative, and immunological parameters in crayfish ( Astacus leptodactylus ). Four hundred fifty crayfish were acclimatized under controlled laboratory conditions and distributed into 15 experimental groups using a definitive screening design (DSD) approach. The groups were exposed to varying combinations of Cd (0, 20, and 40 µg/L), MP (0, 50, and 100 mg/L), and Pec‐supplemented diets (0%, 0.25%, and 0.5% per kg feed) for 45 days. The findings showed that Pec supplementation increased superoxide dismutase (SOD) and glutathione (GSH) peroxidase (GPx) activities but did not affect catalase (CAT) activity. Cd and MPs reduced SOD, CAT, and GPx activities, with Pec partially restoring CAT activity. Exposure to Cd and MPs elevated alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, triglycerides, cholesterol, creatinine, and glucose levels, while gamma‐glutamyl transpeptidase, lysozyme, total protein, and albumin decreased. Pec normalized triglyceride and alkaline phosphatase (ALP) activity but showed limited protective effects on GPx, cholesterol, creatinine, and glucose regulation. The results indicated that because crayfish were directly exposed to MPs and Cd, oral administration of the Pec supplement failed to restore some biochemical parameters to normal levels. These findings indicate Pec’s selective efficacy in mitigating Cd‐ and MP‐induced stress in crayfish.
Kheirandish et al. (Thu,) studied this question.