Four species of walking sharks have late been identified in the waters of northerly Australia and New Guinea . The news program may trigger image of horror films where gargantuan predators chase bather up the beach , but the reality is less alarming . Even in Australia , not everything is endeavor to kill you . Now the first transmissible comparison of the genus is teaching us about these unusual Witwatersrand - dwellers and the region ’s bionomic history .
“ At less than a cadence long on fair , walking shark present no threat to mass but their ability to hold up grim oxygen environments and walk on their louvre gives them a remarkable edge over their prey of small crustaceans and molluscs , ” saidDr Christine Dudgeonof the University of Queensland in astatement .
All walking shark drown , but use their fins to walk across Reef at small tide when the water system is shallow enough to make that the most energy - efficient way of getting around .
No shark outside the genus , even take the air shark ' closest relatives the bamboo shark , have adopted similar physical body of motivity , although several families of bony fish havehit uponthe conception .
Until recently , however , marine biologists consider many walking shark part of a single speciesHemiscyllium ocellatum . Dudgeon is part of a project that has study the shark in more detail andgraduallydemonstrated that those inhabit waters around New Guinea are different enough from the Great Barrier Reef - dwellingH. ocellatumto deserve assortment as four raw species , bringing the full turn to nine .
Dudgeon told IFLScience the trunk shapes and behavior of allHemiscylliumare interchangeable , with the departure only being visible in their color scheme . The variance hinted at in their design , however , is confirm in the shark ' genetic science . Moreover , Dudgeon allege : “ None of the species ' geographic range appear to overlap , ” although she is concerned to see if studies in the Torres Strait may change this .
InMarine and Freshwater ResearchDudgeon reports using mitochondrial DNA to map how each species concern to the others , and or so when separation occurred .
With more roving creatures we might not be able-bodied to make much use of this , but Dudgeon tell IFLScience walking sharks appear remarkably bind to their location for maritime species . “ Bony Witwatersrand fish are site - attached as grownup , but circulate themselves during the larval stage , ” she articulate , while most sharks are quite fluid as adults .
Walking shark , on the other hand , appear to seize territory slowly . raw mintage formed when populations became cut off from each other , either by change in sea storey or tectonic uplift around highly volcanic New Guinea . These never move into each other ’s territory when the barriers were removed , depart the region ’s geologic and climatic history written in their genes .
