Aussie 'ghost fish' species once thought to be extinct is making a 'quiet comeback'

Yahoo

11-07-2025

An Aussie species once thought to be extinct is making a 'quiet comeback' in a farm dam in rural Victoria. Over the past 50 years, climate change and river regulation has decimated the population of flat-headed galaxias — a native animal that once thrived in the southern Murray Darling Basin but has since earned the nickname 'ghost fish' partially due to its declining numbers.
The critically endangered 'floodplain specialist fish' used to be prevalent in NSW, Victoria and South Australia, thriving in wetlands and billabongs, but has now 'basically become extinct' in the latter, North Central Catchment Management Authority (CMA) project manager, Dr Peter Rose, told Yahoo News Australia this week.
'It's only been found in one spot in NSW since 2012 and it's only been found at a handful of sites in Victoria in the last 20 years,' he said. 'They were last seen in Victoria in 2016 in a creek that had since completely dried out, hence our concern.'
Hoping to bring the species back from the brink, the CMA and the Arthur Rylah Institute began surveying dozens of sites in 2022, using eDNA testing — a process that allows scientists to identify genetic material in water — to identify any remaining populations.
'When we started working on them, we weren't even sure whether they were still around anywhere, and we urgently needed to get out and assess whether the species still occurred in Victoria and where the remnant populations might be,' Dr Rose recalled.
Luckily, researchers were able to collect ghost fish from four areas in the state's northeast, which were then translocated to the farm dam to breed.
Given ghost fish struggle to reproduce in captivity, Dr Rose said he wasn't sure the surrogate site would be successful, yet much to everyone's delight, when experts returned months later they were able to catch 50 juveniles, which were then moved to other secure bodies of water.
View this post on Instagram
A post shared by Goulburn Broken CMA (@goulburnbrokencma)
🎣 Banning of 'morally outrageous' fishing trap a major win for elusive animal
🐠 Young Aussies flock to river to return fish 'missing for more than a century'
🔥 Growing $157 billion problem Australia can't afford to fix
As of June this year, a total of four surrogate sites are housing ghost fish populations.
'We just need to secure them, and then once we've got the numbers, we can start trying to put them back into into wild sites where they've become locally extinct,' Dr Rose told Yahoo.
And while they 'haven't boomed as much' as other species bred using the same method, including the southern purple-spotted gudgeon fish, positive results are emerging.
'We captured one that was 161mm — that's larger than previously recorded. And I guess it shows just how healthy these fish are and that they're thriving in these surrogate habitats,' the project manager said.
'This species, along with another five fish species — we call them the magnificent six — are declining right across the southern Murray Darling Basin. These fish are really important food sources for larger fish and water birds, and they play a really important role in the ecosystem as well.
'So to have these species on the brink of extinction is a real worry, and we really need to rehabilitate the wetlands and bring these fish back in.'
Do you have a story tip? Email: [e-mail].
You can also follow us on Facebook, Instagram, TikTok, Twitter and YouTube.