“Why horn shark?”
Well, they’re a member of the Heterodontidae family, meaning they have that characteristics spine in front of each dorsal fin. Therefore, horn shark.
They also have a blunt head (hence “bullhead”) and large crests above its eyes. Their most distinguishing feature is the dark harness pattern on the dorsal side of its body, stretching onto its sidesThey are grey to brown in color, with a white belly, and have black bands on the back and sides of their bodies. Another band is across their face and over their eyes. A few other features include an adorable small mouth (seriously, look at that teeny tiny mouth) and how the nostrils are connected to the mouth through grooves. They also have anal fins!
They are nocturnal bottom-dwellers, found in shelf waters as deep as 902 ft (275 m). In the day, they are found in caves, resting. During their mating season (August-November), they lay their eggs close to shore, and therefore younger Port Jackson sharks frequent the shallows. Although it has not been confirmed, they are thought to know where other pupping/resting sites are and commit them to memory. It’s also thought that they are separated by level of maturity and sex, with a bit of evidence backing that theory up.
These sharks are oviparous, meaning they lay eggs. Egg capsules of these sharks are pretty unique, with a cone like structure. The double helix wraps the capsule and is a protective covering. It’s an olive green color, and eventually darken to brown.
Not much is known about the predators of Port Jackson sharks. However, they probably fall prey to larger sharks (especially while in their egg cases, as Wikipedia user Taso Viglas captured).
They are rarely targeted by recreational fisheries (as slow moving, they’re not really “fun” to catch), and aren’t used for food. They ARE used for science, though, and usually caught as bycatch.
The Port Jackson shark is currently listed as "Lower Risk/Least Concern" by the IUCN Red List.