Horn shark populations remain stable but the impacts of warming waters should remain closely watched.

Morphology

Horn sharks are mottled grey and brown with prominent black or dark brown spots. The white non-toxic spines (‘horns’) in front of each dorsal fin give the shark its name. Horn sharks maximum length is 1.22 meters with females typically larger (longer) than males. A typical adult shark weighs 6.8 kilograms.

They have sharp front teeth to grasp prey that is slippery while their back teeth are more like flat molars to crush their prey with shells. This is what gives them their Greek-origin name Heterodontus, or ‘different teeth’.

Habitat and Range

Horn sharks are found on the sea floor in coastal areas with a variety of cover including rocky reef, kelp forest, and sandy bottom from Central California (Monterey Bay) to the Gulf of California. They are typically found at shallow depths of less than 20 meters but have been observed as deep as 200 meters. Juveniles tend to be found in shallower, warmer areas (<10 meters), whereas adults are in cooler, deeper habitats.

Range Map

Reproductive Biology and Life History

Horn sharks mate in December-January and females can lay up to 24 corkscrew-shaped eggs, in a single season. The eggs are the same color as kelp and are approximately 13 centimeters long. Their corkscrew shape allows them to stay wedged in rocky areas or crevices. Following a 6-9 month incubation period, the eggs hatch into sharks measuring 15-17 centimeters long.

Horn sharks reach sexual maturity at 6-10 years of age, possibly earlier when in human care. ​​Maximum life span is thought to be 25 years, but is not well-documented.

Ecology

As nocturnal foragers , ​​horn sharks tend to rest and shelter in caves and crevices during the day, to protect their light sensitive eyes, and become active at night. Horn sharks are important predators that eat primarily benthic, or bottom-dwelling, animals including crustaceans, sea urchins, molluscs and small fish. Their predators include ​other ​sharks, marine mammals such as sea lions, and other large fish. Their horns aid as a defense and shelter anchoring mechanism.

Limited genetic studies suggest that sharks do not travel long distances over deep water or open ocean, such as between coastal areas and the Channel Islands. This is a behavior trait shared by other benthic elasmobranchs in the region.

Horn sharks have high site fidelity, or in other words they stay in the same place. Adults have been observed to return to the same resting place each day while foraging at night ​​and their home range is estimated at approximately 8-10 hectares.

Horn sharks can appear to walk along the seafloor with their pectoral fins when searching for food at night.

Cultural Significance and Historical Context

Horn shark spines are made into jewelry. Some anecdotal reports suggest that collection of sharks for this use at popular dive sites is impacting local populations. However, there is no official study documenting this impact.

Date modified: April 2026