Effect of sodium hypochlorite in triploid induction in Clarias gariepinus for wild waters stocking, conservation and management

Abstract

Nigeria wild waters is being depleted of Clarias gariepinus due to fishing pressure without the ability to replenish itself, thus necessitates intervention by stocking sterile Clarias gariepinus. Determination of optimum dosage and duration for treatment that will lead to triploidaization of Clarias gariepinus will make wild water stocking realistic. Eggs were artificially fertilized, and subjected to 1.0 % sodium hypochlorite (10,000 ppm) treatments five (5) minutes after fertilization at varied dosages of 1 ml/l, 2 ml/l and 3 ml/l for 5, 10, 15, and 20 minutes then incubated at 28±1 °C for 24 hours. The fertilized eggs treated and untreated were compaired for survival and hatchability. Water quality parameter taken are within the acceptable range: Temperature (25.5-26 0C), dissolved oxygen (6.04 mgl-l-6.50 mgl-l), conductivity (300-320 µs) and pH (6.40- 7.00). 1.0 % sodium hypochlorite (10,000 ppm) at dosages of 1 ml/l, 2 ml/l and 3 ml/l for periods of 5, 10, 15 and 20 minutes significantly affected fertilized eggs (P≤0.05), as dosages of treatments increased, fertilized eggs survival and hatchability decreased. Treatment with dosage 1 ml/l at duration of 5 minutes produced better fertilization and hatchability compared to other dosages. The expected sterile fishes can be used in stocking wild water bodies to increase availability without genetically pollution, reduce endangerment and leading to effective management.