Scientists found hammerhead sharks have twin cousin
The newly found scalloped hammerhead shark faces similar existential threats as its look-alike fishy cousin.
Researchers recently discovered a new species of scalloped hammerhead shark, yet unnamed, that closely resembles its endangered look-alike.
The recent findings suggest that previous estimates of the number of hammerhead sharks was likely inflated since they had included the newfound species. The reason for the late identification is explained by the roughly 20 fewer vertebrae the new species have and differences in their DNA.
"It's a classic case of long-standing species misidentification that not only casts further uncertainty on the status of the real scalloped hammerhead, but also raises concerns about the population status of this new species," said Mahmood Shivji, professor at Nova Southeastern University, LiveScience reports.
The new species was originally detected in 2005 off the eastern coast of the United States, when Shivji’s research team was examining the DNA of sharks initially perceived to be hammerheads due to their physical characteristics.
Genetic assessment shows that approximately 7 percent of the sharks detected in US waters originally thought to be scalloped hammerheads belong to the newly discovered species, as scientists from Nova Southern University and the University of South Carolina had confirmed.
Chronic overfishing and finning had resulted into the dramatic reduction of shark populations around the globe and growing concerns about the impact their eventual extinction might have to the ocean ecosystem.
"It's very important to officially recognize, name and learn more about this new hammerhead species and the condition of its populations through systematic surveys," Shivji said, according to the United Press International. "Without management intervention to curtail its inadvertent killing, we run the risk that overfishing could eradicate an entire shark species before its existence is even properly acknowledged."
Although finning is banned in the US, it is estimated that 73 million sharks are killed annually to support a booming international trade. Shark finning is the process in which fishermen cut of their fins and sell them to mainly Asian markets where it constitutes the main ingredient in a traditional soup delicacy. It is a lucrative trade since these species are sold for about $120 for every 2.2 lbs.
Their length ranges from roughly 13 to 20 feet long and weigh from 500 to 1000 pounds, according to National Geographic.
Although the hammerhead is considered as harmless to humans, it is a keen hunter that uses its heavily serrated teeth to capture its prey, consisted of stingrays, squid, octopus, and other sharks.
Hammerhead sharks first appeared 20 million years ago and belong to the family of Sphyrnidae, named as such due to their strangely-shaped flattened heads with protruded eyeballs at each end, a trait that has made the species into one of the most recognizable fish in the world.