Horned and Hidden: Meet California’s Spiky Little Night Shark
This month’s Monthly Chomp features the horn shark. The horn shark (Heterodontus francisci) may look tough with its spiky fins and camouflage coloring, but this little shark is more shy than scary. Found along the rocky reefs and kelp forests of Southern California and Baja Mexico, it spends its days resting on the seafloor and comes alive at night to hunt. Those venomous dorsal spines? Just for defense. Horn Sharks pose no threat to humans—but we may pose one to them. While this species sticks to the eastern Pacific, its cousins in the bullhead shark family live in oceans around the world. Scientists still don’t know enough about their populations, so more research is needed to protect these fascinating nighttime wanderers.
Horn Shark At-A-Glance
Scientific Name: Heterodontus francisci
How big are horn sharks? Can grow to 4ft/~120 cm.
Where do horn sharks live? Temperate waters of the Pacific Ocean, typically spanning from California coasts to the coasts of western Mexico. Horn sharks typically inhabit the rocky reefs, as well as the algal beds and kelp forests.
What do horn sharks eat?: The majority of a horn shark’s diet consists of bivalve (like clams) and mollusks, sea urchins, and small crustaceans. They have also been observed eating cephalopods (like squid) and small bony fishes.
Do horn sharks lay eggs?: Yes, horn sharks lay eggs! Horn sharks are oviparous, laying spiral shaped shells outside of their wombs. Horn shark eggs are often observed in between crevices and under rocks.
How long do horn sharks live?: Horn sharks can live up to 25 years in the wild, yet only live on average up to 12 years in captivity.
What is the IUCN conservation status? Data Deficient
They are subject to many of the common threats facing sharks.
Are horn sharks endangered?: Data deficient
Do any laws exist protecting the horn shark? Not specifically. Information on current laws and loopholes regarding sharks can be always be found on the Shark Angels site.
Frequently Asked Questions
Are horn sharks aggressive? Horn sharks are not generally aggressive, but can become defensive if they feel threatened.
Why are they called horn sharks? Horn sharks get their name from the horns located on their dorsal fins. These horns are venomous, an adaptation that helps minimize the likelihood of them being consumed by various predators.
Do horn sharks lay eggs? Yes, horn sharks do lay spiral cased eggs. Their eggs can be found wedged between rocks and crevices.
How big are horn sharks in California? Horn sharks can grow up to 4 feet (120 cm).
Bet you didn’t know this about the horn shark….
- Unlike many other shark species, the horn shark does not rely as heavily on electroreception. In comparison to other species that have over 2,000 ampullae of Lorenzini, this species only has 148. Horn sharks rely more heavily on their sense of smell to locate prey.
- Horn sharks have venomous spines on each of their dorsal fins, as well as one on their anal fin. These spines are a form of defense, helping to dissuade predators from consuming them.
- Horn sharks are primarily nocturnal and are behaviorally sensitive to environmental light levels. When environmental light levels are high, horn sharks will typically seek shelter and rest, then will become active and hunt when environmental light levels are low.
- Horn sharks use suction to capture their prey. Structures around the shark’s jaw called the labial cartilage allow the horn shark to turn their mouths into a tube-like shape which helps facilitate suction.
- Horn sharks have the highest known bite force relative to their size. This bite force allows the horn shark to crush through the hard shells and armor of their food.
Ready to Dive In?
Looking to come face-to-face with a horn shark? (Learn more about how responsible shark diving can support conservation efforts here.)
1. Heisler Park
Where: Laguna, California
Best Time: All year round with peak sightings in February and March.
La Jolla Park
Where: San Diego, CA
Best Time: SAll year round with peak sightings in February and March.
Loreto Bay National Park
Where: Loreto, Mexico
Best Time: All year round with peak sightings in February and March.
Science in the Spotlight: How Horn Sharks Slurp up their Snacks
Horn sharks aren’t just cute—they’re clever hunters too. A new study shows that these bottom-dwelling sharks use powerful suction to slurp up their prey, even when it’s tucked into tight spaces. Their jaw movements stay the same no matter how tricky the meal, but when food is stuck, they get creative—leveraging their fins, doing little headstands, and using their whole bodies to yank it free. This combo of suction and smart body tricks helps horn sharks thrive on the seafloor, where prey is often hidden or hard to reach.
After Bites Horn Shark Quiz
Take the horn shark trivia quiz and test your new found knowledge.
Article written by: Greer Jessie, B.S. in Biology with an Anthropology Minor, 2025 College Graduate, University of Florida, and Shark Angels intern.