Production of Monosex Male Population of Red Tilapia In Hapa-Based System Using Velvet Bean (Mucuna pruriens) Ethanol Extract - Dizon, Rica Rose S. (Magalang, Pampanga : Pampanga State Agricultural University, 2020)
This study aimed to determine the potential sex reversal property of velvet bean (Mucuna pruriens L.) seed ethanol extract in red tilapia in a hapa-based system. A total of 750 one-week old post-hatch fries with approximately similar body weights were grouped into five treatments with three replicates each. Treatment 1 was assigned as the positive control having 60 mg/kg methyltestosterone. Treatment 2 and Treatment 3 were given 200 mg/kg and 300 mg/kg ethanol extract of velvet bean, respectively, without zinc sulfate. Treatment 4 and Treatment 5 were given 200 mg/kg and 300 mg/kg ethanol extract of velvet bean, respectively, with zinc sulfate. The experimental animals were randomly allocated in a pond with hapa net enclosures using completely randomized design (CRD). Administration of the velvet bean ethanol extract was done for a period of three weeks; normal feeds was given after the treatment period until desired growth has been achieved. Different water parameters were regularly checked during the experimental feeding. After which, the animals were euthanized for the collection of gonads for phenotypic sex determination.Data gathered were percent primary production, male percentage in different treatments, initial weight, final weight, weight gain, feed conversion rate, actual numbers of fish stocked and fish survived, survival rate, water temperature, dissolved oxygen, turbidity, pH, total ammonia nitrogen, nitrite and chlorophyll content which were statistically analyzed using one-way analysis of variance (ANOVA). The treatments were statistically significant (P>0.05) in the male percentage, survival rate, gain in weight, FCR, chlorophyll analysis and other water quality parameters. The results suggest that M. pruriens has male sex inversion potential in red tilapia. Furthermore, the treatments had no adverse effects on general fish health and water quality parameters.