horn shark

fish

Also known as: Heterodontus francisci

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July 17, 2026

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The horn shark, scientifically known as Heterodontus francisci, is a small species of shark native to the eastern Pacific Ocean, specifically off the coast of California. It is related to the bullhead shark and is characterized by its broad head, short snout, and small mouth.12

Horn sharks are harmless to humans and primarily feed on mollusks, crabs, and sea urchins, possessing teeth adapted for crushing and grinding. They are oviparous, meaning they lay eggs, which are distinctively screw-shaped with a spiral flange. These sharks are found in tropical waters and are part of the larger group of cartilaginous fishes known as sharks.234

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7 Animals that Lay the Most Unusual Eggs
Marine corkscrews of sharks
The horn shark (genus Heterodontus) is a sluggish animal that crawls the ocean floor between central California in the U.S. and Baja California, Mexico. Female horn sharks lay eggs encased in corkscrew-shaped cases—each case bearing a single baby shark. These egg cases range from 7.5 to…
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The horn shark (genus Heterodontus) is a sluggish animal that crawls the ocean floor between central California in the U.S. and Baja California, Mexico. Female horn sharks lay eggs encased in corkscrew-shaped cases—each case bearing a single baby shark. These egg cases range from 7.5 to…
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bullhead shark
…conduct population surveys of the horn shark (H. francisci) of the eastern Pacific Ocean, whitespotted bullhead shark (H. ramalheira) of the western Indian Ocean, and the Oman bullhead shark (H. omanensis) of the Persian Gulf and Arabian Sea.
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…conduct population surveys of the horn shark (H. francisci) of the eastern Pacific Ocean, whitespotted bullhead shark (H. ramalheira) of the western Indian Ocean, and the Oman bullhead shark (H. omanensis) of the Persian Gulf and Arabian Sea.
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chondrichthyan
Reproduction and development
…less pillow-shaped; those of the horned sharks (Heterodontus francisci) are screw-shaped with a spiral flange. The eggs of chimaeras are elliptic, spindle-shaped, or tadpole-shaped and open to the exterior through pores and slits that permit entrance of water during incubation. An egg of the whale shark found in the Gulf…
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…less pillow-shaped; those of the horned sharks (Heterodontus francisci) are screw-shaped with a spiral flange. The eggs of chimaeras are elliptic, spindle-shaped, or tadpole-shaped and open to the exterior through pores and slits that permit entrance of water during incubation. An egg of the whale shark found in the Gulf…
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