Like other members of its family, the Japanese bullhead shark is oviparous.

However, most bullhead sharks caught in these fisheries survive to be released alive.

The whitespotted bullhead shark is found on the outer continental shelf.

Harmless to humans, the Japanese bullhead shark can be easily hand-caught by divers.

Crested bullhead sharks are oviparous with a possibly annual reproductive cycle.

The bullhead sharks are a small order of basal modern sharks (Neoselachii).

The head of the crested bullhead shark is short and wide, with a blunt, pig-like snout.

Innocuous towards humans, the crested bullhead shark is of little interest to recreational or commercial fisheries.

The crested bullhead shark is a slow-moving, nocturnal species often seen wedging its head between rocks in search of food.

The egg cases of bullhead sharks (Heterodontidae) have spiral flanges that allow them to be wedged inside crevices.

Unlike the Port Jackson shark, the crested bullhead shark is not known to form large aggregations.

Crested bullhead sharks are likely also caught in mesh shark nets used to protect beaches; again, most are able to survive the experience.

Like other bullhead sharks, the horn shark has a short, wide head with a blunt snout and prominent supraorbital ridges over the eyes.

There are nine living species of bullhead shark, with another potential undescribed species in Baja California:

Japanese Bullhead Shark (hidden fish)

Order Heterodontiformes (bullhead sharks)

The Mexican hornshark, Heterodontus mexicanus, is a bullhead shark of the family Heterodontidae.

Heterodontus japonicus (Japanese bullhead shark)

The Japanese bullhead shark is a docile, slow-swimming species that feeds mainly on shelled invertebrates and small bony fishes.

Heterodontus galeatus (Crested bullhead shark)

Heterodontus omanensis (Oman bullhead shark)

Heterodontus quoyi (Galapagos bullhead shark)

Heterodontus ramalheira (Whitespotted bullhead shark)

Bullhead shark (Heterodontus sp.)

Heterodontus zebra (Zebra bullhead shark)

There are nine living species in a single genus, Heterodontus, in the family Heterodontidae.

Subsequent authors moved this species to the genera Gyropleurodus and Molochophrys before placing it in Heterodontus.

This species was later placed in the genus Gyropleurodus, which was eventually synonymized with the genus Heterodontus.

Horn Shark (Heterodontus francisci)

Other common names used for this species include bull head, cat shark, Japanese horn shark, Cestracion shark, and Port Jackson shark (which usually refers to Heterodontus portusjacksoni).

Formerly known from only two specimens, further museum specimens were discovered at the Museum of Comparative Zoology of Harvard University in the 1990s, having been misidentified as Squatina and Heterodontus.

They are not serrated, and the front teeth have a very different shape from those found at the back of the jaws, hence the genus name Heterodontus (from the Greek heteros, meaning 'different', and dont, meaning 'tooth').