Dwarf Galaxias
Galaxiella pusilla
The Dwarf Galaxias is one of Australia’s smallest native freshwater fish, growing to just 40 millimetres in length. Slender and almost transparent, it has an olive to golden-brown back, silvery sides, and a series of dark bars and spots that provide excellent camouflage amongst aquatic vegetation.
Native to south-eastern Australia, the Dwarf Galaxias occurs in Victoria, Tasmania and parts of South Australia. Despite its tiny size, it plays an important role in freshwater ecosystems by feeding on small aquatic invertebrates while also providing food for larger native fish, birds and other wetland wildlife.
Moonlit Sanctuary is working in partnership with the Victorian Government (DEECA), the Bunurong Land Council Aboriginal Corporation and other conservation partners to help secure the future of this remarkable species. Through our captive breeding program, we are carefully managing breeding to maintain genetic diversity within the captive population before releasing fish into carefully selected wetlands. These releases help strengthen existing populations and restore the species to areas where it has disappeared.
Habitat
Dwarf Galaxias inhabit shallow freshwater wetlands, swamps, marshes and slow-moving waterways with abundant aquatic vegetation. These plants provide shelter from predators, breeding sites and habitat for the tiny invertebrates they feed on.
Many of the wetlands they inhabit experience natural seasonal fluctuations in water levels, including periodic drying. Unfortunately, many of these habitats have been drained, fragmented or altered by changes to natural water flows, leaving isolated populations scattered across a much smaller range than they once occupied.
Protecting and restoring these wetlands is essential to the long-term recovery of the species.
Diet
Dwarf Galaxias feed on tiny aquatic invertebrates, including insect larvae, water fleas, copepods and other microscopic animals found amongst wetland vegetation.
At Moonlit Sanctuary, young fish are carefully raised on specialised live foods, including rotifers and newly hatched brine shrimp (Artemia). Producing these live food cultures is an important part of the breeding program and helps maximise the survival and growth of delicate fry during their first weeks of life.
Threats
The greatest threats to Dwarf Galaxias are the loss and degradation of wetlands, altered water regimes and the introduction of invasive fish such as Eastern Gambusia (Gambusia holbrooki), which compete with and prey upon eggs and young fish. Climate change is also expected to place increasing pressure on the shallow wetlands the species depends upon.
By restoring habitat, managing threats and supplementing wild populations with captive-bred fish, conservation organisations are helping give this unique species the best possible chance of recovery.
Breeding
Moonlit Sanctuary has developed dedicated breeding systems that carefully recreate the environmental conditions Dwarf Galaxias experience in the wild. Seasonal changes in temperature, daylight hours and specially designed spawning habitats encourage the fish to breed naturally.
Breeding groups are carefully managed to maintain genetic diversity within the captive population, helping ensure released fish contribute to healthy, resilient wild populations. Detailed monitoring of breeding, egg development and fry growth allows our team to continually refine the program and improve breeding success.
