Freshwater fish of Australia facts for kids

Australia is a huge continent, even bigger than the contiguous United States. Yet, it has only about 280 types of freshwater fish. This might seem like a small number for such a large landmass.

One big reason for this is Australia's dry climate. Much of the continent is desert, with rain falling only sometimes. Fish cannot live in many of these dry areas, especially in South Australia and Western Australia. Most freshwater fish in Australia live in warmer, wetter places, like tropical or subtropical regions.

Unique Australian Fish

Many freshwater fish found in Australia are endemic. This means they live naturally only in Australia and nowhere else in the world.

Temperate Perches

A family of fish called Percicthyidae, also known as temperate perches, is very important in Australia's freshwater systems. They are a dominant group here. In other parts of the world, like the Northern Hemisphere, fish families like the carp family (Cyprinidae) are usually the most common.

No Native Carp

Interestingly, no carp species are native to Australia. However, the common carp (Cyprinus carpio) was brought to Australia illegally. These introduced carp have caused a lot of damage to the native fish populations and their homes.

Galaxiidae Fish

The Galaxiidae family of fish has also become very important in Australia. Most of the world's Galaxias species are found here and in nearby New Zealand.

The Murray-Darling Basin

One of Australia's most important freshwater systems is the Murray-Darling Basin. This huge river system drains about 13% of the entire continent.

Home to Big Fish

The Murray-Darling Basin is home to some of Australia's most significant freshwater fish. This includes the Murray cod, which is Australia's largest freshwater fish.

Threats to Australian Freshwater Fish

Since Europeans first settled in Australia in 1788, Australian freshwater fish have faced many challenges. Many of these fish are not well understood, and human activities threaten them.

What Harms Fish?

Many things put these fish at risk:

• Clearing riverbank plants: Removing plants along rivers (called riparian vegetation) means fish lose their shelter and food.
• Siltation: Dirt and mud from farms can wash into rivers, making the water cloudy and harming fish habitats.
• Removing snags: Fallen trees and branches in rivers, called "snags," are important hiding places and homes for fish. Removing them destroys these habitats.
• Overfishing: Catching too many fish can reduce their numbers too much.
• Dams and weirs: Building dams and weirs on rivers changes the natural flow of water and can block fish from moving to different areas.
• Introduced fish and diseases: Fish brought from other countries can compete with native fish for food and space, or they can spread diseases.

Endangered Species

Sadly, some native fish populations have already disappeared. The Richmond River cod and the Brisbane River cod are now extinct. Many other species are listed as endangered or critically endangered, meaning they are at high risk of disappearing forever.

See also

In Spanish: Peces continentales de Australia para niños