Researchers have long known that the Nile tilapia feeds on mosquito larvae but the study was the first to test its potential to fight the disease in the field, said Annabel Howard and Francois Omlin, researchers at the International Centre of Insect Physiology and Ecology in Nairobi.
"A fish in the field may act differently than a fish in an aquarium and it was important to test how effective it could be. The tilapia species was never tested in the field for its ability to eat mosquito larvae," said Omlin.
The researchers introduced Nile tilapia (Oreochromis niloticus L.), to deserted fishponds in western Kenya. The study, funded by the Government of Finland, BioVision Foundation (Switzerland) and the Toyota Environment Foundation, monitored the pond life, comparing the restocked ponds with a control pond nearby.
After 15 weeks the fish reduced both Anopheles gambiae s.l. and Anopheles funestus, the region's primary malaria vectors, by over 94 percent. The fish also decimated three quarters of the culicine mosquito population.
The findings present a win-win situation for Kenyans, who can use the fish to limit mosquito populations and gain food and income from them too.
"O. niloticus fish were so effective in reducing immature mosquito populations that there is likely to be a noticeable effect on the adult mosquito population in the area," Howard says.
The findings of the study are published in the BioMed Central (BMC) journal.