SUBLETHAL EFFECT OF METHANOL LEAVES EXTRACTS OF KHAYA SENEGALENSIS ON GROWTH AND FOOD UTILIZATION OF THE AFRICAN CATFISH CLARIAS GARIAPENIUS

O. A. Abui, M. M. Matouke

Abstract: The effect of sub-lethal concentrations 39.93 mg.L-1, 19.97 mg.L-1 and 9.98 mg.L-1 of methanol leaves extract of Khaya senegalensis on growth and food utilization were investigated on juveniles’ African catfish, Clarias gariepinus for a period of five months (February-June 2015). The growth rate was significantly reduced (P < 0.05) in fish exposed to the methanol extract K. senegalensis compared with the control group. Nutrient utilization showed that, specific growth rate (SGR), Feed conversion ratio (FCR), Gross feed conversion efficiency (GFCE), Feed efficiency (FE), protein efficiency ratio (PER) and Nitrogen metabolism (NM) were significant (P < 0.05) in the control fish compared to the exposed fish. Similarly, the percentage crude protein and oil content were significantly higher (P < 0.05) in the control than the exposed. The study revealed that K. senegalensis altered the growth and food utilization of C. gariepinus. Therefore the monitoring of K. senegalensis near productive
aquatic ecosystems is recommended.

Keywords: Clarias gariapinus; growth; Khaya senegalensis; sublethal toxicity

Date published: 2017-09-04