ENVIRONMENTAL MONITORING AND ASSESSMENT: A CASE STUDY OF THE BIOCHEMICAL AND HEMATOLOGICAL PROPERTIES OF Coptodon zillii AND Oreochromis niloticus FROM UREJE RESERVOIR IN EKITI STATE

Abstract

The health of aquatic organisms, especially fish, can serve as a reliable indicator of environmental conditions in freshwater ecosystems. This study assessed the biochemical and haematological parameters of Coptodon zillii and Oreochromis niloticus from Ureje Reservoir in Ekiti State, Nigeria, to determine the physiological status and potential exposure to environmental stressors. Blood samples were analyzed monthly (October-December) for key haematological indices including packed cell volume (PCV), red and white blood cell counts (RBC, WBC), haemoglobin (Hb), and differentials, as well as biochemical parameters such as albumin, creatinine, urea, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). Results revealed species-specific variations, with C. zillii generally showing higher values of RBC (3.40 x 1012/ml), WBC (21.03 x 109/ml), PCV (29.83%) and Hb (9.72 g/100ml) compared to O. niloticus (2.92 x 1012/ml, 19.87 x 109/ml, 24.20% and 9.04 g/100ml respectively), whereas O. niloticus had elevated ALT (49.28 mg/dl), AST (21.60 mg/dl), and urea (43.15 g/100ml) levels compared to C. zillii (38.32 mg/dl, 18.49 mg/dl, and 38.43 g/100ml, respectively), possibly indicating greater environmental or physiological stress. Albumin levels were higher in C. zillii (45.60 g/100ml), whereas creatinine values were relatively similar across species. These findings suggest potential ecological impacts and highlight the usefulness of haematological and biochemical biomarkers in monitoring fish health and water quality.