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Port Jackson Shark
Threat Level: low
Scientific name.........Heterodontus Portusjacksoni
Other name...............Oyster crusher or tabbigaw
The Port Jackson shark, also called the oyster crusher or tabbigaw, is very similar to the related California hornshark. These sharks are unmistakable, with their blunt foreheads, pig-like snouts, and broad eye ridges.
These sharks can measure up to a maximum length of 5.4 feet, but rarely exceeds 4.6 feet. Males mature at 27- 31 inches, females at 31-37.4 inches. The pups measure between 9 - 9.4 inches long.
They have small pointed teeth at the front of the jaw and blunt teeth at he rear. With these, they can grab soft- bodied fish and crustaceans, and crush sea urchins.
Port Jackson sharks are gray to light brown or whitish with unique distinctive black striped "harness" marking. No spots. Dark between and under eyes.
These sharks feed mainly on sea urchins, other benthic invertebrates, also small fish.
Port Jackson sharks rest by day in groups on sand in a few favoured caves and gullies, some traditional collective egg-laying sites are used. Hatchlings move to nursery grounds nearby until adolescent, when they move well offshore and segregate by sex , joining the adult population a few years later. Adults segregate by sex, undertaking complex seasonal breeding migrations. Some males and all females move to inshore reefs in July to breed, returning offshore after mating (males) and egg laying (females). Some adults remain offshore in summer, others migrate south up to 850 km from breeding areas.
They inhabit in Southern Australia, from Queensland to mid-Western Australia, including Tasmania, rare in New Zealand. They occur in temperate waters, from intertidal zone to a depth of at least 900 feet.
No data found.
In Australia, females and some males in the Sydney area move into shallow water in summer to mate. In August and September, females lay two eggs every 8-17 days among rock crevices in 16-100 feet of water, often in a communal nursery. The female will wedge the pointed edge and flanges of the screw-shaped egg case into a rocky crevice using her mouth. The young hatch 9 to 12 months later and move into bays and estuaries. After a decade, they will have grown to 20-30 inches and have reached adolescence.
Generally sedentary, harmless unless handled.
Abundant. Taken as bycatch but mostly returned alive, Kept and bred in captivity.
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