Heterodontiformes, also known as bullhead sharks are an ancient order that are now represented by one family. This month we’re showing off one of the bullhead sharks, the Port Jackson Shark. This species was first documented in Port Jackson, the inlet containing Sydney Harbour, Australia.

Grey to light-brown, they have a distinct ’harness’ marking - a stripe across the eyes which links around to their backs. Nocturnal, they rest by day, often in groups in or near caves – foraging during the night.

They live in separate groups based on sex and life stage. They’re migratory within their range. And they have complicated seasonal breeding migrations.

Their teeth are different in the front and back. Their back teeth are flat and blunt, perfect for grinding and crushing the shells of their prey. They eat crabs, shrimp, squid and other bottom dwellers. Their front teeth are small, sharp and pointed. They can eat and breathe at the same time. This is unusual for sharks, as most species need to swim with their mouths open to force water over their gills. Port Jacksons can pump water through their first gill slit allowing them to remain still on the seafloor for long periods.

 

An unusual feature of the Port Jackson Shark is their spiral shaped eggs. Females can wedge them into cracks and crevices where they are held in place by the corkscrew-like grooves.

Listed as least concern by the IUCN. The Port Jackson Shark is abundant. Whilst it is taken as bycatch by fisheries, it’s of no value for food and so most are returned alive.

We're pleased to announce that our partners at The Great Out-tours have created a £1 activity bundle featuring the Port Jackson Shark!

 

Click the image below to check it out!

SCIENTIFIC NAME:  Heterodontus portusjacksoni

FAMILY:  Heterodontidae

MAXIMUM SIZE:  165cm

DIET:  Bottom-dwelling invertebrates and small fishes

DISTRIBUTION:  Australia

HABITAT:  Intertidal to at least 275m. Sandy caves, gullies and sandy bottoms next to rocky reefs

CONSERVATION STATUS

Images by Ian Donato

Eggcase Image via Kiddle Encyclopedia