EFFECTS OF IN VITRO MELATONIN EXPOSURE ON THE HEMATOLOGICAL AND PLASMA LIPID INDICATORS OF JUVENILE AFRICAN CATFISH

This study examined the impact of melatonin exposure on hematological and lipid indicators of juvenile African catfish. A total of 135 fish were randomized into three groups: 0-, 10-, and 30 mg/L of melatonin for 14 days, followed by 7 days of withdrawal. Hematological and lipid changes were determined using standard bioassays. The results showed that melatonin caused a significant elevation in total white blood cell counts and a significant reduction in red blood cell counts, packed cell volume, and hemoglobin concentration in a duration- and concentration-dependent manner (p ≤ 0.05). Changes in WBC recovered after melatonin withdrawal, but RBC, PCV, and HB changes persisted. Furthermore, significant interactions were observed between melatonin concentration and exposure duration in all hematological indicators. However, no significant changes in plasma lipid indices were recorded (p ≥ 0.05), which indicates that exogenous melatonin profoundly affects the hematology but not lipid metabolism of young catfish