Four species of walking sharks have been discovered in the waters off northern Australia and New Guinea.
To many a human terrified of sharks, there is solace in the fact that sharks live in the water and we live on terra firma – as in, sharks can't swim on land, phew. But evolution loves to turn things on end ... and guess what? Now we have sharks that can walk!
But fear not, the only ones who need to worry about this development are small fish and invertebrates, say the University of Queensland (UQ) researchers who recently discovered four new species of walking sharks.The strolling sharks were discovered during a long-term study between Conservation International, the CSIRO, Florida Museum of Natural History, the Indonesian Institute of Sciences and Indonesian Ministry of Marine Affairs and Fisheries.
UQ research fellow Dr. Christine Dudgeon says that the festively patterned sharks were the top predator on reefs during low tides when they used their fins to walk in very shallow water, explains the university.
"At less than a metre long on average, walking sharks present no threat to people 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," she says.
"These unique features are not shared with their closest relatives the bamboo sharks or more distant relatives in the carpet shark order including wobbegongs and whale sharks."
Before the new discovery, there were five species of walking sharks known to science; with the four new ones, there are now nine. But, says Dudgeon, "We believe there are more walking shark species still waiting to be discovered."
So how did these ambling fish learn to walk? Dudgeon says they believe that the sharks ended up in a different area from their brethren, and the new environment created new requirements.
"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," she says.
New species that can put one fin in front of the other and take a stroll like the rest of us landlubbers, that is.
You can see in the video below how this might give the sharks an advantage when seeking out prey. They are low to the ground and have more control than might be afforded when swimming. Mother Nature never fails to amaze.
The study was published in the CSIRO's Marine and Freshwater Research journal.