The world's first hybrid shark was discovered off the coast of Australia, researchers from the University of Queensland said on Tuesday. Jess Morgan, lead researcher on the project, said that this hybridization could potentially be caused by the sharks need to adapt to climate change and the warming ocean.
This is evolution in action, Morgan told the Agence France-Presse news organization.
The hybrid is a result of a mating of the Australian black-tip shark with the common black-tip shark, and may be better suited than its parent species. We don't know whether that's the case here, but certainly we know that they are viable, they reproduce and that there are multiple generations of hybrids now that we can see from the genetic roadmap that we've generated from these animals, said Colin Simpfendorfer, a partner in Morgan's research. Certainly it appears that they are fairly fit individuals.
The Australian black-tip is smaller than the common black-tip, and lives only in tropical waters. The hybrid, however, were found over 1000 miles down the coast, in much cooler waters, meaning that the shark could be adapting to temperatures caused by 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 to the AFP. It's enabled a species restricted to the tropics to move into temperate waters.
The hybrids were numerous, accounting for up to 20 percent of black-tip populations. However, Morgan said that these new hybrids didn't replace their single-breed parents, which adds to the mystery.
We thought we understood how species of sharks have separated, but what this is telling us is that in reality we probably don't fully understand the mechanisms that keep species of shark separate, Simpfendorfer said in the study, published in Conservation Genetics last month. And in fact, this may be happening in more species than these two.