Mosquito Fish

Scientific NameGambusia affinis
Common Name(s)Mosquitofish, Mosquito fish
OriginMississippi River Basin; Illinois, Indiana
Temperature Range68-82°F
pH Range6.5-8.0
Adult Size3in
DietOmnivore; mosquito larvae, other live food

Mosquitofish Facts:

1. They are nicknamed ‘Mosquito-fish’ because their diet is mostly mosquito larvae.

2. Their Latin name ‘Gambusia’ means useless.

3. Female Mosquitofish can consume as much as 150% of their own body weight in mosquito larvae in one day.

Male Mosquitofish

Male Mosquitofish

Female Mosquitofish

Female Mosquitofish

Species Overview:

Mosquitofish are a tiny freshwater pond fish native to North America and parts of Mexico. As a species they usually do not grow larger than 3”, with the females being much larger than the males.

They were introduced to many other countries as pest control, and are therefore present in a number of countries including Australia. Mosquitofish are highly adaptable to a wide range of temperatures and water conditions making them suitable for use in many different countries.

Since Mosquitofish mainly eat Mosquito larvae as their name would suggest, they were introduced to reduce the natural populations of mosquitoes in many countries, and reduce the spread of diseases such as malaria and West Nile Virus (diseases which mosquitoes act as a vector for).

Although their name would suggest that their main food source is mosquito larvae, the species do eat other types of insects and vegetation from their habitat such as zooplankton. Mosquitofish cannot survive on mosquito larvae alone. When kept as pets they may also eat fish flakes.

Mosquitofish usually live for 1-2-years in the wild, with a maximum of 3 years when kept as pets. They give birth to live young and produce 3-4 broods per year of around 60 fish each brood. The Gestation period takes around 1 month. The young usually reach sexual maturity within 2 months for males and one month for females (depending on when in the season they are born).

Mosquitofish can be useful when kept as pets in your own man-made freshwater pond by eating algae, other vegetation and insect larvae and keep the pond looking nice. They should not however be released from your pond or aquarium into the wild. They can detrimentally affect natural ecosystems.

When kept as pets it’s not essential to feed them often unless there is a lack of insects/algae or it is a new pond. Mosquitofish should NOT be put in new ponds (especially concrete ponds) as concrete leeches lime and that will make Mosquitofish sick (by altering the pH of the water).

The Mosquito Fish requires at least 20 gallons with moderate water temperature and plant life for hiding from predators like possums, cats and birds.

Posted on August 14, 2014 and filed under Freshwater Fish.