Fast Facts: Port Jackson Sharks

  • Port Jackson Sharks are easily identifiable by the harness-like markings which cross the eyes, run along the back to the first dorsal fin, then cross the side of the body.
  • Port Jackson Sharks belong to the family Heterodontidae, which have eight species, all in the genus Heterodontus, three of which are found in Australian waters. These are the Port Jackson Shark, the Zebra Horn Shark and the Crested Horn Shark.
  • Whilst diving and freediving, I’ve found them laying on, around and under rocky environments near or on the bottom. Sometimes they are found in sandy or grassed areas.
  • Port Jackson Sharks are very laid back and they are not known to harm. If you have a fear of sharks, then these super chilled sharks may be a positive experience for you.
  • They love eating black sea urchins, molluscs, crustaceans and fishes and are night hunters.
  • During the day, they relax and protect themselves under caves and rocky outcrops.
  • Port Jackson Sharks have an unusual ability to eat and breathe at the same time. Many sharks can’t do this.
  • When they hatch, juvenile Port Jackson Sharks, called pups, are about 25 cm long.
  • The breeding season is usually late winter and into spring. During this time, I’ve seen “Port Jackson City:” literally dozens and dozens of Port Jackson Sharks hanging out under caves and ledges on a single dive!
  • The female’s lay eggs. The egg case is a tough, dark brown spiral about 7 cm to 8 cm wide and 15 cm long. You can see them wedged under ledges or between rocks, for safety. One young shark emerges after ten to twelve months.
  • Females reach maturity at 11 to 14 years and males at 8 to 10 years.
  • The sharp spines of small individuals are an excellent defence mechanism, however, the spines become blunt as the shark matures.
  • They are the easiest species of horn shark to see and are abundant in Sydney.

References: Own personal experience, https://australianmuseum.net.au , “Close Encounters with Marine Life” by Nigel Marsh and “Diving with Sharks” by Nigel Marsh and Andy Murch.

Published by Karina Teuma

karinateuma.com Karina Teuma is a Passionate Marine Biology Enthusiast, Environmentalist, Snorkeller, Freediver, Scuba Diver and more.

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