In an effort to control the spread of malaria and dengue, the health department has introduced gambusia fish into water bodies to check the breeding of larvae in stagnant water.
A health department official said that the fish, also known as mosquitofish, will be introduced into 115 natural and 23 seasonal water bodies across the city.
Following showers over the last few days, water has stagnated at several area and it could lead to the breeding of Aedes mosquito, the carrier of dengue virus.
A single, fully grown gambusia fish eats about 100 to 300 mosquito larvae per day.
The cost of introducing larvivorous fish is relatively low compared to the cost of fogging machines and spraying larvicide oil in drains. The option is eco-friendly too compared to other methods.
“Since the fish feeds on mosquito larvae and requires no other food, it has a low maintenance cost,” a health department official said.
The health department has been breeding gambusia fish since last month following directions from the state government as a precautionary measure against waterborne diseases.
After breeding, the fish were transported to health centres across the city. Health officials then identified area prone to mosquito breeding and started releasing this fish into ponds and stagnant water in these areas.
“The growth of mosquitoes can be effectively tackled using gambusia fish, which primarily feed on mosquito larvae. Fish has been transported to local and periphery areas, where there is breeding of mosquitoes,” senior district malaria officer said.
The fish measures between 8 mm (at birth) to 50 mm (adult) and is capable of consuming larvae nearly 40 times to its weight (100 to 300 mosquito larvae a day).
Gambusia can only be bred in summer and has a lifespan of two to three years. It has a preference for shallow water where mosquito larvae also breed.
Last year, the city had reached a three-year high in dengue cases with the district health department registering 401 cases. In 2012, 375 cases were reported , while 175 were reported in 2013 and 86 in 2014.