Histological Analysis of Female Redbelly Tilapia; Tilapia zillii (Gervais, 1848) Ovary, Fed Bitter Melon, Momordica charantia (Cucurbitaceae) Leaf Meal

Abstract

This research was carried out to control tilapia population using Momordica charantia leaf meal as reproduction inhibitors. A total of 150 post juvenile Tilapia zillii female fish, weighing 30.36+or-0.13 g were used. The leaf of Mormodica charantia (Bitter melon) was added to a basal diet (35% crude protein) at 0, 20, 40, 60 and 80 g/kg diets and fed to female Tilapia zillii for 80 days. The fish were distributed in triplicate into 15 plastic tanks (1x1x1 m) at a stocking density of 10 fish per tank. Borehole water with pH value between the range of 6.90-7.67, temperature range between 25.4-26.6 degrees C and dissolved oxygen; 2.8-3.9 ml/l were used. The water volume of 400 litres was maintained throughout the period of experiment. The fish was fed at 4% body weight/day in two installments at 09:00-09:30 hs. Histological examination of ovary in T. zillii fed 0 g of MCLM/kg diet showed no visible lesions nuclei of follicle cells were prominently seen while in treatment containing 20 g of MCLM/kg, few oocytes was seen in the ovary and there was generalized congestion, 40 g MCLM/kg diet section showed necrosis of the ovary, few oocytes were found in the ovary. In fish fed 60 g MCLM/kg diet, necrosis and abnormal gonadal development was noticed and ovary was devoid of oocytes. In fish fed 80 g MCLM, highly abnormal gonadal development and necrosis was noticed. Phyto chemical analysis of Momordica charantia showed the presence of charantin, alkaloids, momordicins, tannin, steroid, saponin, terpeniod and glycosine. There was decrease in fecundity (from 286 to 100), relative fecundity (from 3.91 to 1.24), and gonadosomatic index with increase in level of treatments used. Histological observations and fecundity analysis of T. zillii fed high dietary MCLM diet levels revealed that Bitter melon leaves may be effective as sterility-inducing agents in T. zillii.