Home News Once-extinct ‘zombie fish’ are back for a wild time

Once-extinct ‘zombie fish’ are back for a wild time

Southern purple-spotted gudgeon (Mogurnda adspersa), feared extinct in Victoria, have been released into the wild. Image credit: AAP Image/North Central CMA/Doug Gimesy

The native southern purple-spotted gudgeon (Mogurnda adspersa) was declared extinct in Victoria in 1998, before two were discovered near Kerang in the state’s north in 2019.

The North Central Catchment Management Authority resolved to get the freshwater fish, dubbed “zombie fish”, thriving again after the find.

A program to breed an “insurance” population of the endangered fish, in partnership with Melbourne’s SEA LIFE aquarium, was declared a success after the first eggs hatched on New Year’s Day.

Nine months on, breeders released the fish into McLartys Lagoon, a natural wetland on the mid-Goulburn River in Victoria.

The fish are small and purplish-brown to yellowish-brown, with a rounded head and a small mouth.

During the breeding season, which spans from November to March, the fish display their bright colours of blue wash with red spots, which they are characteristically known for.

Once the eggs are laid, the male fish will care for them, guarding and fanning them until they hatch, which takes between three and nine days depending on the temperature of the water.

The fanning of the eggs ensures sediment does not build up and smother the young fish before they can hatch.

“Now that the (young) have developed to around 2–3cm long, we have returned them into pest-free ‘surrogate’ sites in the wild to expand the population,” aquarium curatorial supervisor Samuel Fawke said.

It is the first time SEA LIFE Melbourne has bred and released native fish into the wild.

Other populations of the zombie fish have been released in different wetlands in Victoria.

Southern purple-spotted gudgeon fry are about 15mm in size, although they can reach 15cm. Males reach maturity at about 4.5cm and females at about 5cm in length.

They feed off live and pre-made foods and like to live in dense reeds.

The aquarium worked with the Goulburn Broken Catchment Management Authority and the North Central authority for the release, which happened ahead of National Threatened Species Day on Thursday.

Visitors and locals to Melbourne can see the southern purple-spotted gudgeon at the SEA LIFE aquarium.

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