Western Rainbowfish - Upper Katherine River

Melanotaenia australis (UKR)

General information: Western rainbowfish are very different over their range. The specimens at the headwaters of the Katherine River are much different to specimens near the town of Katherine. Up the tributaries of the Katherine and Daly Rivers they can be different colours, with the specimens in the Ferguson River having yellow fins. It is always worth a look at the fish when you can get into a new area because you may find one that is really different to the others. When one hears about a possible nice rainbowfish in a remote location it is time to make some travel plans to do some exploration. During August 2009 some fish finding friends were visiting and we set out to do some exploring. The Werumbun Association and Jaywon Association agreed to let us into Arnhem Land to look for small fish. The arrangement is to have small fish in captivity and breed them for the aquarium hobbyists, sell the small fishes and return a percentage of the farm gate sales back to the land owners to help manage their lands. This way a natural resource helps pay for the landowners to control invasive pests which are getting into the most remote places imaginable. The sustainable use of natural resources is a way forward for land managers to make an income form lands that are perhaps not suited for farming or grazing. It is also a form of conservation when a resource is valuable in its natural state and earning some income it gives the area added value. We flew by Helicopter about 100 kilometers over Kakadu National Park toward Arnhem Land to the east and onto the top of the Arnhem Land Escarpment near the source of the Katherine River. The other Rivers that arise in this part of the country are the Roper River and South Aligator Rivers. Tony, the owner of the Helicopter landed on a sandy flat beach next to the river and we spent a couple of hours collecting about 50 small rainbowfishes for brood stock. The photos are from left to right, landing with the fish back at Mary River Roadhouse. The upper Katherine River, two pictures of young males in various poses. The females are much more subdued in their colouration.

Cultivation notes : They were kept in a small Aquarium and treated for capture shock and fungus by the Doc, Bruce Hansen. After about two weeks they had settled to captive life and started to breed. The conditions they were kept was temperature 27 deg C, hardness 30 ppm, carbonate hardness 20 ppm and pH 7.2. They were fed plankton from the ponds and grew quite quickly.

Distribution : Western Rainbowfish have a large distribution over the top of the NT and WA.

Selling details : Sold as individuals 3 cm or larger

Reference: Allen, Midgley & Allen (2002) "Field Guide to the Freshwater Fishes of Australia"