Two-spined Blackfish (Gadopsis bispinosus)
Description
- Two-spined Blackfish are a yellowish-brown to olive green colour, with dark brown ‘giraffe’ spots.
- They're usually less than 30 cm long and weigh up to 200 g.
- They can be hard to spot and blend in well with their watery surroundings.
- These fish rarely move far from their homes with adults usually active during dawn and dusk.
- They feed on insect larvae, mayflies, and caddisflies, midges, and terrestrial invertebrates.
- Two-spined Blackfish can live up to 8 years.
- Females start laying eggs after 2 years, and can lay up to 240 eggs a year.
- They attach and hide their eggs between rocks in a nest to keep them safe.
- The male fish stays and looks after the eggs.
Find out more about the Two-spined Blackfish on Canberra NatureMapr.
Where to find them
- This species lives in the cooler parts of the upper parts of the Murray–Darling River system in Victoria, NSW, and the ACT.
- In the ACT, you can only find them in the Cotter River, usually upstream of the Cotter Reservoir.
- They like to live in cool, clear streams with rocks and boulders for shelter, and sometimes in upland reservoirs.
Conservation threats
The Two-spined Blackfish survival can be in danger if there are:
- changes to their habitat
- river regulation causing lack of water or water at the wrong time
- barriers to fish passage
- sedimentation
- poor water quality
- introduced fish species
- climate change.
Sedimentation is one of the biggest threats to the Two-spined Blackfish. This is because they lay eggs on or between rocks and sedimentation covers the rocks and fills in the spaces between. This often happens after wildfires, heavy rain or because of forestry practices.
Conservation status
- Australian Capital Territory – Vulnerable (Nature Conservation Act 2014)
Conservation actions
Conservation actions aim to:
- limit sediment from getting into rivers
- make sure there are plants to shade the river
- create more places for the fish to live, such as expanding their preferred habitats or connecting different populations
- continue to learn more about the fish and the threats they face to improve protection efforts
- encourage the community to help protect these fish and understand fish conservation.