Scientists discovered four new species of sharks that can walk
After 12 years of research, an international group of scientists has discovered four species of ‘walking sharks,’ almost doubling the thus far known species count of these strange and rare creatures.
And while you may be picturing a shark chasing you on two feet, that isn’t how the physiology of these animals works – and there’s nothing to be afraid of when it comes to these species found in the waters between New Guinea and northern Australia (unless you are a small fish, that is).
“At less than a metre [3.3 ft] long on average, walking sharks present no threat to people,” stated biologist Christine Dudgeon from the University of Queensland in Australia.
“But their ability to withstand low-oxygen environments and walk on their fins gives them a remarkable edge over their prey of small crustaceans and molluscs.”
The astounding shark species are part of the genus Hemiscyllium family. Members of this group were connected to five existing shark types thanks to genetic analyses, using samples of tissue from living specimens found during the research.
“We estimated the connection between the species based on comparisons between their mitochondrial DNA which is passed down through the maternal lineage,” she says.
“This DNA codes for the mitochondria, which are the parts of cells that transform oxygen and nutrients from food into energy for cells.”
The findings showed that the DNA of the newfound animals was consistent with that of the existing Hemiscyllium species, which can be traced back to the Late Cretaceous period, which spanned between 66 to 100 million years ago.
Given the cosmic time scales involved and the giant scope of international waters, it can be hard to pinpoint exactly how and why these walking sharks came to evolve.
“It can be challenging to identify the forces that drive speciation in marine environments for organisms that are capable of widespread dispersal because their contemporary distributions often belie the historical processes that were responsible for their initial diversification,” the researchers explained in their paper.
We can, however, speculate. In this case, the scientists suggest Hemiscyllium may have in fact hitch-hiked around the planet while geographical shifts emerged over immense spans of time, as tectonic activity and sea-level changes moved the positions of island chains and reefs.
“Data suggests the new species evolved after the sharks moved away from their original population, became genetically isolated in new areas and developed into new species,” Dudgeon says.
“They may have moved by swimming or walking on their fins, but it’s also possible they ‘hitched’ a ride on reefs moving westward across the top of New Guinea, about 2 million years ago.”
The researchers say that other shark species probably exist too.
It is just a matter of discovering them.
You can see footage of the newly-found shark species in the video below.
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