“They can withstand quite low oxygen levels, so they live in quite shallow environments and when the tide goes out the sharks stay on the reef flat and can move around to feed by walking on their pectoral fins.”
This means the sharks walk through the shallow water of the reef flat and even lift themselves entirely out of the water to move between shallow pools at low tide.
The sharks identified by the research team are part of the carpet shark group that also includes the wobbegong, and are found from Coral Bay in Western Australia to the southern Great Barrier Reef and in waters around New Guinea.
Scientists previously believed the epaulette shark (Hemiscyllium ocellatum) was the primary species of walking shark across the region, with four species identified.
But after more than a decade of research they have now confirmed that there are nine separate but closely related species of shark that can all walk.
“Genetic 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,” Dr Dudgeon said.
“It is a unique adaptation and it means they can exploit a habitat that other predators can’t.”
After expanding the number of known species from four to nine with the most recent research, Dr Dudgeon said there were likely to be other species of walking shark out there still waiting to be discovered.
But she reassured those who were worried that the sharks were unlikely to be any longer than a metre, putting to rest visions of great white-sized terrors lurching from the surf onto the nation’s beaches.
“White sharks have their own amazing adaptations but walking, fortunately, is not one of them,” she said.
The study also involved representatives of Conservation International, the CSIRO, Florida Museum of Natural History, the Indonesian Institute of Sciences and Indonesian Ministry of Marine Affairs and Fisheries.
The research has been published in the CSIRO’s Marine and Freshwater Research journal.
Stuart Layt covers health, science and technology for the Brisbane Times. He was formerly the Queensland political reporter for AAP.