Jenni's Beach Adventure Journal
Monday the 11th of April, 2022
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Diggers Beach, Northern NSW
Did you know that sharks can lay egg cases? While most shark species give birth to live young, the Pork Jackson sharks lay egg cases in a corkscrew shape...mmm why?
Let's learn about Port Jackon Sharks first: better known as "PJ sharks".
So PJ sharks are nocturnal, bottom dwelling with a "bull head". They are not huge sharks, growing up to around 1.65m and live for around 30 years. As their name suggests they are named after Port Jackson in Sydney.
What makes these sharks a little bit unique? Well, it's the fact that they lay eggs (not live births as a lot of other sharks do). But not just any egg, the females lay pairs of corkscrew shaped eggs.
To protect their eggs the mumma shark uses her mouth to wedge her precious eggs into cave crevices where it stays for around 10 to 12 months. The baby sharks (called pups) that emerge are super cute at only 25cm long. The empty egg cases are often found washed up on the beach.
Journal Photo 1
You can see that this PJ shark egg case would have washed up onto the beach with the tides (hint: it's in the bottom right-hand corner). I was super lucky to find some of these on an afternoon walk on the beach.
Journal Photo 2
Amazing to think that a shark emerged from this egg under the sea.
Watch this documentary as the next generation of Port Jackson sharks hatch into their aquatic world alone and must learn fast in order to survive.
