SUB-LETHAL EFFECT OF PAWPAW LEAVES (Carica papaya) EXTRACTS ON GROWTH, SURVIVAL AND HAEMATO-BIOCHEMICAL CHANGES OF Clarias gariepinus

Abstract

The effects of Carica papaya (pawpaw) leaf extract on Clarias gariepinus juveniles (mean weight 22.50±0.02 g) were assessed under laboratory conditions, focusing on growth and haematological parameters. The 48-hour lethal concentration (LC₅₀) was determined as 8.0 ml/L. Fish were exposed to sub-lethal concentrations of 0.00 (control), 0.04, 0.08, 0.15, 0.30, and 0.60 ml/L for 28 days, with 10 fish per tank in triplicate. Data were analysed using ANOVA at P = 0.05. Growth parameters showed no significant differences (P>0.05), but weight gain and specific growth rate declined with increasing extract concentration. Survival was highest in PL5 (95.00±5.00%), with significant differences among treatments (P<0.05). Haematological responses varied with concentration. Packed Cell Volume (PCV) increased slightly in treated groups, except PL2 (42.00±2.83%), PL3 (41.00±2.00%), and PL6 (40.00±2.00%). Haemoglobin (Hb) peaked in PL4 and PL5 (15.00±2.83 g/dl) compared to control (14.3±2.83 g/dl). Red Blood Cell (RBC) counts declined in most groups except PL3 and PL4 (5.10±2.83×10⁶/l). White Blood Cell (WBC) values dropped overall but increased in PL4 (17.6±2.83×10⁶/l) and PL5 (18.00±2.83×10⁶/l). Significant differences (P<0.05) were observed in Total Protein (TP) and Albumin (ALB), while Globulin (GLO) showed marginal increases, except in PL3 (35.00±2.83 g/dl). These findings indicate that sub-lethal concentrations of C. papaya leaf extract affect the growth and blood parameters of C. gariepinus, and may have potential as a natural piscicide for pond management