Vol. 5, Issue 3, Part A (2018)

Author(s): Aga Abebe, P Natarajan and Abebe Getahun

Abstract: Oreochromis niloticus weighing 3.8±0.9gm and length 4.6±0.9cm and Tilapia zillii weighing 3.4±0.76 gm and length 4.7±1cm were tested for their efficacy on devouring of mosquito larvae (Anopheles and Culex) in an aquarium tank with a size of 30cm x38cm x30cm containing 2.5 litres of pond water. The number of III and IV instars of mosquito larvae consumed was recorded in three hour interval for 24hrs in day and night. The larvae were identified, stored and treated at the same time and separately with light and aeration on and off. A total of 3025 larvae were fed to the fishes; 1679 for Oreochromis niloticus and 1346 for Tilapia zillii during the experiment. O. niloticus and T. zillii consumed 111 and 89 mosquito larvae/fish/24hrs, respectively. Field experiment was carried out in a pond with a size of 6m (l) x 8m (w) x 0.42m depth. O. niloticus (3.5±0.8cm and 4.1±0.85gm) due its high larval devouring capacity were used for the field experiment. The results showed a significant reduction (92%) of mosquito larvae in the field experiment.