The horn shark, Heterodontus francisci, is a bullhead shark. It can reach a size of 122 cm and is brown with black spots. Its range is from central California to the Gulf of California, Mexico, and probably also in Ecuador and Peru. It is mostly nocturnal and appears sluggish in the daytime. It can bite if it is harassed.
Its habitat includes rocky reefs, kelp beds, sand flats, crevices, and caverns in a depth range from 2 to 150 m. Adults tend to return to the same resting spot every day. It feeds on invertebrates, primarily sea urchins, crabs, probably abalone, and other fish.
The horn shark is oviparous, laying 12–14 cm (5 inches) long kelp-colored spiral-shaped eggs that may float up on beach shores.
