Fishy battle against dengue

By Risidra Mendis 

Having a pond in your home garden or a fish tank in your house can be a lot of fun especially if you happen to be a lover of ornamental fish. However despite the many varieties of ornamental fish available in the market and the thriving business of ornamental fish export, many people think twice about having a fish tank or pond in their garden these days, for fear that this could become a breeding ground for the dengue mosquito larvae.

However unknown to many, a number of ornamental fish are known to devour any type of mosquito larvae. The dengue mosquito lays its eggs between 9 a.m. and 5 p.m. in clean water. The water, if not cleaned daily can become a breeding ground for the dengue mosquito. However, the simplest way to prevent the dengue mosquito from spreading, not to mention getting out the water containers on a daily basis, is to put some ornamental fish that consume mosquito larvae into a pond or tank.

Deceptive scavenger

Ornamental fish come in a variety of colours blue, green, yellow, orange, red and pink shades, and are even known to derive unusual colours through interbreeding. However in a bid to sell and promote the scavenger fish, certain fish breeders are deceiving their customers by telling them that this type of fish eats mosquito larvae. 

Speaking to The Sunday Leader, Managing Director, Lumbini Aquaria Wayamba Ltd, Vibhu Perera confirmed that the scavenger fish is a vegetarian and does not devour mosquito larvae. "As far as I know a scavenger is generally used by professional fish breeders and fish enthusiasts, to clean the formation of algae from tanks and ponds," Perera said.

According to Perera almost all types of fish are carnivorous and eat all kinds of mosquito larvae. The Combtail Paradise fish (Belontia signata), Red LinedBarb Wild (Puntius bimaculatus), Rainbow Panchax Wild (Aplocheilus dayi), Green Panchax Wild (Aplocheilus lineatus), Aplocheilus Panchax, Black Spot Barb Wild (Puntius filamentosus (juv) ), Giant Danio Wild (Danio malabaricus), Black Ruby Barb (Puntius nigrofasciatus), Black Sport Barb (Puntius filamentosus), and the female Cherry Barb Wild (Capoeta titteya) are all known to consume insect larvae.

"It is a known fact that mosquito larvae are considered to be a delicacy for ornamental fish" says Perera. 

Guppies and fighters

Meanwhile former President, Association of Specialised Aquarium Fish Breeders of Sri Lanka, Claude Juriansz said guppies are the ideal fish to get rid of mosquito larvae. Other fish known to eat mosquito larvae are the angels, Siamese fighters, plates and swordtails.

According to Juriansz, carps and goldfish are specifically known to refrain from eating mosquito larvae.

Juriansz went on to say that guppies and Siamese fighters are ideal for fish tanks while angels, plates and swordtails will do fine in ponds.

Apart from ornamental fish native fish are also known to eat mosquito larvae. However the interest among the general public is to buy and breed ornamental fish as some varieties of native fish are endemic to Sri Lanka and cannot be reared in houses and public places.