SCIENTISTS have found the world's first hybrid sharks in Australian waters.
Leading researchers in marine biology discovered 57 animals along a 2000 km stretch from Queensland to NSW.
The predators are a cross between the common blacktip shark and Australian blacktip shark, two related but genetically distinct species.
The scientists say interbreeding between the two shark species is a sign the animals are adapting to climate change.
They also warn that hybridisation could make the sharks stronger.
Dr Jennifer Ovenden, of the Queensland Department of Primary Industries and Fisheries, said: "Hybridization could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favours tropical waters in the north while the larger common black tip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline."
She added: "Wild hybrids are usually hard to find, so detecting hybrids and their offspring is extraordinary. To find 57 hybrids along 2000km of coastline is unprecedented."
Dr Jess Morgan, a researcher at the University of Queensland researcher, told The Australian that it was unusual for sharks to breed in this way.
"Sharks physically mate, which is usually a good way to make sure you don't hybridize with the wrong species," she said.
Colin Simpfendorfer, of James Cook University's Fishing and Fisheries Research Centre, said: "The results of this research show that we still have a lot to learn about these important ocean predators."