Critter Science

The Science of Animals

Port Jackson shark

Chilling with the Port Jackson Shark

The Port Jackson shark, aka the oyster crusher, is the largest of the Heterodontid sharks. The dorsal fins’ spines are one of the reasons for the common name, “Horn shark”. These sharks reside in the tropical waters of southern Australian, from south Queensland to Tasmania, and west to the central coast of Western Australia at depths of up to 900 feet. These sharks are typically seen chilling on the ocean bed awaiting evening time, which is dinner time.

First the Stats…

Scientific name: Heterodontus portusjacksoni
Weight: 125 lbs +/-
Length: 5.4 feet
Lifespan: 20+ years

Now on to the Facts!

1.) These sharks are real multitaskers as they can eat and breathe at the same time!

2.) They don’t have to constantly swim to move oxygenated water over their gills. They can open and close their mouths to pump water over their gills. This is called buccal pumping.

3.) The preferred habitat is sandy, rocky, or muddy areas on the ocean bottom, and they also reside in areas where seagrass grows.

4.) Port Jackson sharks are nocturnal (active at night).

5.) Bullhead sharks are also found in the same areas as the Port Jacksons.

But wait, there’s more on the Port Jackson shark!

6.) Nighttime feeders as they are, they feast on small fish, sea urchins, sea stars, polychaete worms, prawns, gastropods, and crabs.

7.) Jacksons have two kinds of teeth: the front teeth are small and sharp for grabbing and holding prey items, and the back teeth are flat and broad (like molars) that are used for crushing and grinding shells.

Did you know…?
The egg case is an alien-like, dark brown, spiral-shaped casing that’s about 2.8 x 7″ in diameter that comes out soft, is wedged into rock crevices and left to harden.

8.) Female Port Jacksons become mature at 11 – 14 years old, while males do so at 8 – 10 years.

9.) The eggs hatch after 10 – 12 months! A single pup emerges from each egg case and the pups are about 10 inches long.

10.) Even though they are capable of inflicting a painful bite, they typically pose no threat to humans.

Now a Short Port Jackson Shark Video!

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Critter Man

With over 40 years of critter experience to my credit and hundreds of zoology teaching hours to people around the world, I have amassed not only a continuing thirst for critter knowledge but a desire to teach others all I can about the majesty and wonder of our natural world. Critter Science is a culmination of such knowledge.I have hands on as well as book acquired intel on all kinds of critters. Whether they're on land, sea, or air.I will never say that I know everything about all animals. That's impossible, even for a savant. But, that being said, ask me any animal question and I'll answer it. If I don't know the answer, I'll get an answer for you!Let it be said that I have been oft times accused of loving animals more than I love people. I can neither confirm nor deny this.

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