Hematological Responses of Cyprinus carpio to Environmental Toxicants

Abstract

Water bodies face severe environmental pollution risks, and among the riskiest aquatic pollutants are pesticides. Cyprinus carpio is a cosmopolitan fish species found in freshwater that is extremely sensitive to toxic substances and is a very good bioindicator of aquatic ecosystem health. This study tested the hematological effect of lambda-cyhalothrin, a pyrethroid pesticide, on Cyprinus carpio using Mean corpuscular volume (MCV), hemoglobin, hematocrit measurements, white blood cell (WBC), and red blood cell (RBC) counts  after a 14-day exposure. Temporal changes were assessed by blood sampling on Days 0, 7, and 14. The results indicated lambda-cyhalothrin exposure caused significant reductions in RBC, hemoglobin, and hematocrit levels, indicating impaired oxygen transport, but with increased WBC counts, suggesting an immune reaction to toxic stress. The observations demonstrate the negative impacts of pesticide exposure on fish physiology and justify the application of hematological biomarkers as sensitive markers of aquatic contamination. The research provides the critical information necessary for understanding lambda-cyhalothrin sublethal toxicity and highlights the necessity for strict regulation and pesticide runoff monitoring of freshwater ecosystems. Effective biomarker-based surveillance tools are essential for the protection of aquatic biodiversity and long-term ecological stability.