USE OF CHEMOPROPHYLACTIC AGENTS IN THE MANAGEMENT OF Clarias gariepinus SEED PRODUCTION

Abstract

Some chemotherapeutic agents and procedures haveshown toindividually enhance fish egg hatchability. This paper
reviews the use of such disinfectants (iodine, formaldehyde and hydrogen peroxide), antibiotics (ciprofloxacinmetronidazole), procedure (egg washing) and their combinations on Clarias gariepinus hatchability. One thousand
eight hundred each of washed and unwashed fertilised eggs obtained from both parenteral, prophylactic
ciprofloxacin-metronidazole treated (each 10mg/kg) and untreated broodstock, were disinfected by bath for 15
minutes in three recommended disinfectants: hydrogen peroxide (H2O2; 83.3, 166.7 and 250 ppm), povidone-iodine
(33.3, 66.7 and 100 ppm) and formaldehyde (333, 667 and 1,000 ppm), incubated at 26oC and hatchability
determined. Appropriate controls were set up, data analysed using standard tests at α0.05. Hatchability significantly
improved with egg washing (40.1%), antibiotics (39.8%), 250 ppm H2O2 disinfection (23.5%), over the control. The
combination of egg washing and 166.7 ppm H2O2 disinfection, antibiotics and 83.3 ppm H2O2 disinfection;
antibiotics and egg washing improved hatchability by 53.4%, 50.8% and 46.7% over the control, respectively.
Antibiotics, egg washing, disinfection with 83.3 ppm H2O2 combination gave the highest hatching rate of 76.8%. To
prevent drug resistance, egg washing and166.7 ppm H2O2 disinfection combination is recommended for routine
Clarias gariepinus egg management.