- River regulation
- Persistent growth of exotic weed
- Invasive fish species
Flathead Galaxias or Murray Jollytail used to abound in the freshwater regions of NSW, Australia, especially within the Murray Darling Basin. But very few confirmed sightings have been recorded even after a 15-year extensive scientific sampling carried throughout the rivers of Lachlan, Macquarie, and Murrumbidgee as well as the Murray River.
Adult individuals have a length of up to 150mm. They prefer to stay in still or slow moving waters, especially during the breeding season which starts in spring. Its long slender body has a blotchy texture and an olive green hue though its underside is silver in colour. It is also characterised as having transparent fins, forked tail, and a rather large mouth extending up to the lower part of its eyes.
The Flathead Galaxias is threatened to continuously decline in population due to man-made infrastructure and activities that alter the water levels, diminish water clarity, and disrupt its normal lifecycle. Exotic weed growth as well as the abundance of the illegally introduced Brown Trout and Common Carp also negatively affects this fish species.