Introducing predatory fish could curb malaria

Everyone knows that to conquer malaria you must conquer the mosquitoes that carry the parasite. Could one approach be to enlist the help of a hungry fish?

A new report details how seeding ponds in Africa with tilapia fish causes a dramatic reduction in the number of immature mosquitoes that transmit the deadly disease. Whether the strategy will work as a way of fighting malaria remains to be seen, say experts.

Francois Omlin of the International Centre of Insect Physiology and Ecology in Nairobi, Kenya, and his colleagues selected three ponds with "alarmingly high" numbers of mosquito larvae in the western part of the country to conduct their experiment. They introduced Nile tilapia (Oreochromis niloticus) into two of the ponds, and kept the third as a control.
Feeding frenzy

Water samples revealed that the number of larvae of the mosquito Anopheles gambiae had dropped by more than 80% in the two experimental ponds 15 weeks after Omlin's team added the tilapia. The number of larvae in the control pond tripled within the same period.

And while numbers of another malaria vector – the Anopheles funestus mosquito – remained steady in the ponds with tilapia, they skyrocketed in the control pond.

The researchers say that adding tilapia to fishless ponds could help reduce mosquito populations and thereby fight malaria, which claims more than a million lives worldwide each year, most of them children. As an added benefit, the fish themselves, which breed every few weeks, could become a source of protein and income for local people.
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