All fish / Heterodontidae

Horn Shark

Heterodontus francisci

Also known as california horn shark, bullhead shark, horned shark, pig shark, カリフォルニアネコザメ, 佛氏虎鲨

A small, stocky bullhead shark with a blunt pig-like head, high brow ridges and a sharp spine in front of each of its two dorsal fins. It is grey-brown with scattered dark spots and is kept by public aquariums and very dedicated hobbyists because it is hardy, slow moving and spends much of its time resting on the bottom.

Care at a glance

Care level

Hard

Temperament

Semi

Adult size

90 cm

Temperature

14 to 21 °C

pH

8.1 to 8.4

Smallest tank

3000 litres

Keep as

Singly, or a pair in a very large system

Diet

Carnivore: shellfish, crabs, shrimp, squid, sea urchins and fish pieces

Swims

Bottom of the tank

Lifespan

12 to 25 years

Water

Marine (saltwater)

Wild range

Eastern Pacific: central California to the Gulf of California, Mexico

Breeding

Females lay distinctive corkscrew-shaped egg cases that they wedge into rock crevices, and the young hatch after about seven to ten months. It has bred in public aquariums, but this is rarely achieved in home systems because of the space and cool water required.

Good to know

It needs a chilled, very large tank with a big open sand floor and grows to around 1 m, so it is unsuitable for most home aquariums. The dorsal spines can injure handlers, and it will eat crustaceans, molluscs and small fish kept with it.