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Range and Habitat: Coastal areas of Australia which are temperate and subtropical western South Pacific. Range from southern Queensland, New South Wales, Victoria, and Tasmania. Ranges from close inshore to 172 meters (565 feet). Port Jackson sharks favor caves with sandy floors and open trenches of shallow rocky reefs. Common in shore waters in most of its range.
Description: Maximum length reported is 165 centimeters (about 5.5 feet). Port Jackson sharks usually range from 105 to 123 cm (3-4 feet), however females are often a bit larger than males. The head is conical and slightly elevated, not depressed and wide. Mouth is moderate for body size well in front of the eyes. The skin is grey to light brown or whitish with a prominent black bar across the head and down the cheeks. They also have a horizontal black stripe on the sides of the back and tail. They have 5 pairs of gill slits on each side of head with the last three above the pectoral fin base.
Habits and Adaptations: Front teeth are small, sharp and pointed with the rear teeth more molar like. The Horn shark is sluggish, nocturnal, and mostly solitary. It is seldom seen moving during the daytime but commonly has its head in a crevice. Shortly after dusk this shark becomes active and apparently feeds mostly at night, but ceases activity after dawn. Swimming is slow and sporadic.
Diet: Benthic invertebrates, especially sea urchins, starfish, polychaetes, prawns, barnacles, and small fish.
Breeding and Maturation: Port Jackson sharks are oviparous. Mature females are accompanied by some males into inshore reefs during the breeding season, but most mature males remain in deeper water offshore. Approximate estimates of age at maturity from captivity suggest 8 to 10 years for males and 11 to 14 years for females. The male grabs the female’s pectoral fin, mates, and with in the next two months, eggs are laid. Eggs are deposited in rock crevices on shallow sheltered reefs at depths of 1 to 5 meters (3 – 16 feet). Size at birth is 15 to 16 cm (6 inches). These young are born ready to fend for them selves. Lifespan is unknown.
Miscellaneous: There are blood protein studies that suggest Port Jacksons from different regions form at least two populations, a western-southern one and from western Australia to northeastern Victoria and a northeastern one from New South Wales and possibly southern Queensland. The two dorsal fins have stout fin spines that can make consumption by larger predators more difficult. They are of minimal interest to fisheries probably more from by-catch from the shrimp and bottom-trawling operations. These sharks are harmless unless harassed and grabbed by divers, when it can deliver a painful bite. Larger sharks and fish as well as humans are considered predator to these sharks.
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