Scientists have just discovered the world’s very first hybrid shark off the eastern coast of Australia– and it wasn’t created with science!
Scientists made their discovery while cataloguing shark species off the eastern Australian coast. While doing so, they came across a set of sharks that physically looked like one breed of shark – the Australian black-tip shark. Genetic testing showed, however, that these sharks were actually a descendant of the common black-tip shark.
Slightly smaller than the common black-tip, the Australian black-tip shark is only able to survive in tropical waters. The hybrid shark they discovered has been spotted in cooler waters, at least 2,000 kilometers down the coast, bringing scientists to the hypothesis that the cross-breeding may be an effort to ensure survival by counteracting global warming issues.
“If it hybridises 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,” stated Jess Morgan, a researcher from the University of Queensland.
Human fishing is also being considered as a reason behind the hybridizing, but no one really knows for certain. And apparently, the reason behind the cross-breeding is not the only thing that scientists are uncertain about.
Discovery of the hybrid has scientists pondering several things that they thought they knew, like how the species of sharks have separated over the years. Scientists are wondering if this really is the world’s first naturally occurring hybrid animal.
“We thought we understood how species of sharks separated, but what this is telling us is that in reality, we probably don’t fully understand the mechanisms that keep species of sharks separated,” stated Colin Simpfendorfer, a partner in Morgan’s research from James Cook University. “And in fact, this may be happening in more species than these two.”
In an effort to uncover some answers, scientists are working on genetic mapping. They hope the mapping will help them determine if this cross-breeding has occurred for ages and is just now being discovered or if it really is a new “evolutionary” development.
Either way, it doesn’t seem that the hybrid sharks are cancelling out their pure-bred predecessors. While the hybrid sharks were found to account for up to 20 percent of the black-tip population in some areas, their single-breed parents still seemed alarmingly abundant. Although, at this time, there is no indicator as to whether the hybrid sharks are stronger or more viable than their pure-bred predecessors.
“We certainly 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,” stated Simpfendorfer. “Certainly it appears that they are fit individuals.”