Port Jackson shark
(Heterodontus portjacksoni)
eggs shaped like a corkscrew
Diet
Feeds on sea urchins and gastropods, as well as crustaceans and small fish.
Habitat
Found in temperate waters on the eastern, western and southern coast of Australia.
Fin-tastic facts
From an ancient order of sharks that predates the dinosaurs, Port Jackson sharks look prehistoric. Between July and October, males and females gather in huge numbers around New South Wales in Australia to mate. Two weeks later, females produce the first pair of extraordinary spiral-shaped eggs. These large eggs (nearly the size of the mother’s head!) would have required a considerable energy investment, and so mothers will sometimes carry their eggs in their mouths and wedge them into crevices in the rock. The corkscrew design of the egg makes them difficult to dislodge, so they are kept safe from predators. The unfortunate few that don’t have a safe hiding place make easy pickings for predators. The crested horn shark, which looks almost identical to the Port Jackson shark, is a major predator of Port Jackson shark eggs. They crush the eggs using their strong jaws, feeding off the rich yolk.
