Multiple generations of the shark, a hybrid of the genetically distinct Australian black tip -- whose range extends north from Brisbane -- and the larger common black tip found in southeastern coastal waters, have been found in five locations between northern New South Wales and far north Queensland, The Australian reported Monday.
"Wild hybrids are usually hard to find, so detecting hybrids and their offspring is extraordinary," Jennifer Ovenden of the Queensland Department of Primary Industries and Fisheries said.
"To find 57 hybrids along 2000km (1,200 miles) of coastline is unprecedented," she said.
Some scientists say the discovery suggests shark species might be interbreeding as an adaptation to climate change.
However, other researchers said they could not determine how or even when the hybridization had taken place.
"I don't think it's a result of climate change per se, but it could certainly give the sharks more genes to cope with change in the environment," University of Queensland research scientist Jess Morgan said.
"By mixing their DNA, the species considered more tropical has been able to extend its range into cooler waters," Morgan said.