Scientists find world's ‘mutant’ sharks in Australian waters

Australian scientists have discovered the world's first hybrid sharks off the east coast of the continent – leading imaginative reporters to suggest that it could be a prelude to the eventual arrival of a horror film type mega-predator.

Hybrid black tip shark containing both Common and Australian black tip DNA.Credit: University of Queensland

The scientists involved of course dismiss such sensational conclusions. It is the scale of the discovery that has really astonished them, with multiple generations of the new creature identified in five locations between northern New South Wales and far north Queensland.

The hybrid comes from the Australian black-tip shark mating with the common black-tip. The two are different species; while the former is found only in warmer coastal waters, the latter is distributed globally, including in the cooler waters off southern Australia.

In their study of the marine animals, the marine biologists found that one shark's genetic tests showed it to be a different species than it looked like. The team estimates that as much as 20 per cent of the black-tip population in some areas is the hybrid variety.

A nuclear DNA marker (inherited from both parents) was sequenced to confirm the hybrid status.

Using both genetic testing and body measurements, 57 hybrid animals were identified from five locations, spanning 2000km from northern NSW to far northern Queensland. Although closely related, the two species grow to different maximum sizes and are genetically distinct.