RIVERS OF THE NORTH
THE RIVERS OF NORTHERN AUSTRALIA ARE AFFECTED BY THE TROPICAL SEASONS, PROVIDING A REGULARLY CHANGING HABITAT FOR A UNIQUE, DIVERSE GROUP OF ANIMALS, MANY SPECIES OF WHICH ARE SHARED WITH PAPUA NEW GUINEA.
FRESHWATER CROCODILE
(Crocodiles johnstoni)
The freshwater crocodile and the saltwater species are readily distinguishable by the length and shape of their snouts: long and blunter in the freshwater species, broader and blunter in the saltwater. “Freshies” are also much smaller, growing to no more than 2.5 meters whereas “salties” grow to more than 3 times this size. The freshwater crocodile will bite but unlike the saltwater crocodile has not been known to kill humans.
BARRAMUNDI (Lates calcarifer)
A well known fish of the far north in the Barramundi which forms the basis of a major Australian fishing industry. All Barramundi are born male and when they reach about 4 years of age they start changing into females. Sex change in freshwater fish is uncommon. These fish are very tolerant to changes in the amount of salt in the water and actually migrate to the ocean to spawn.
LUNGFISH (Neoceratodus forsteri)
One of the oldest of all river inhabitants is the Queensland Lungfish which has the ability to take air from the surface into a single lung which allows the lungfish to survive in the dry season when high temperatures and rotting plants reduce the amount of oxygen in the water. Because it is regarded as a living fossil, this fish is protected by state and federal legislation.
