Dire outlook for native freshwater fish with 22 species given less than 50% chance of survival

Biggest threat is non-native fish, but study was conducted before summer bushfires impacted Australia's rivers

• Freshwater hell: scientists race to save endangered fish from bushfire ash

Some 22 native freshwater fish have a 50/50 chance or worse of becoming extinct within two decades unless targeted action is taken to save them, according to new research.

The most threatened fish is Victoria's tiger-striped shaw galaxias which, experts concluded, had an 80% chance of being gone in 20 years time.