The world’s first hybrid shark was discovered recently in Australian waters. The mating of the local Australian black-tip shark with the common black-tip is a potential indicator that sharks are adapting to climate change.
“It’s very surprising because no one’s ever seen shark hybrids before, this is not a common occurrence by any stretch of the imagination,” said lead researcher Jess Morgan, from the University of Queensland. “This is evolution in action.”
This shark was found during cataloging work off Australia’s east coast. Morgan explains that the shark looked like one species, but genetic testing revealed it to be another.
The Australian black-tip only lives in tropical waters and is smaller than the common black-tip. The hybrid offspring have been found 2,000 kilometers away in cooler water. This indicates that the Australian black-tip could be adapting to changing sea temperatures due to global warming.
“If it hybridizes with the common species it can effectively shift its range further south into cooler waters, so the effect of this hybridizing is a range expansion,” Morgan said. “It’s enabled a species restricted to the tropics to move into temperate waters.”
In some areas, the hybrids accounted for up to 20 percent of all black-tip populations. However, their abundance has not negatively affected the population size of their single-breed parents.
Copyright © 2012 by Marine Science Today, a publication of OceanLines LLC