Aquatic Invaders - Introduced species are a threat to our aquatic biodiversity

Mosquito Fish

Gambusia holbrooki

Photo: J Langdon

Although they were introduced from Central America in 1934 to help control mosquitoes, gambusia only eat mosquito larvae if nothing else is available. Native fish, whose eggs they consume, usually eat far more mosquito larvae. Gambusia nip and damage the fins of other fish and their live young survive better than the offspring of egg-laying fish.

Identification

Gambusia are small fish, up to 60mm long. They are olivebrown to bronze or silvery, with a single dorsal fin and the males have a long anal fin. They are often in small schools and may be mistaken for swordtails or guppies.

What you can do

If you catch them, keep and dispose of them humanely. They should not be used for live bait or sold for aquarium purposes and never released or returned to waterways or dams.

Consider using native fish if you need to control mosquitoes.

Reporting the Presence

You can help the Department of Fisheries to keep our inland fisheries healthy. Be on the lookout for these introduced pests. Report their presence to the FISHWATCH service on 1800 815 507.