How Horn Sharks Slurp up their Snacks
This study shows how horn sharks catch food using suction feeding. While their jaw movements stay the same, they use special body tricks to pull out prey that’s hard to reach. This helps them hunt effectively on the ocean floor.
Introduction: What Is the Horn Shark Study About?
This study investigates how the horn shark (Heterodontus francisci), a small shark species found in the eastern Pacific Ocean, captures its food. Researchers wanted to know how its jaw and mouth movements work, and whether the shark changes its feeding behavior based on how accessible the prey is.
How Horn Sharks Feed
Horn sharks use a method called inertial suction feeding.
- They quickly open their jaws and extend special labial cartilages (lip-like structures) to create a vacuum that sucks food into their mouths.
- This technique is common among other bottom-dwelling sharks but different from sharks that chase prey by swimming fast (ram feeding).
Experimental Setup
Researchers tested five horn sharks in captivity.
- The sharks were offered pieces of squid in three ways:
- Unattached (easy to grab)
Attached (secured to a platform)
- Burrowed (snugly fitted into a tube to mimic prey hidden in a crevice)
- Unattached (easy to grab)
They used high-speed video to study jaw movements during feeding.
Main Findings
1. Feeding Movements Are Consistent
- The sharks did not change their basic suction feeding pattern based on prey accessibility.
- They always used the same sequence: rapid jaw opening, suction, and then jaw closing.
2. Special Post-Capture Behaviors
- When food was attached or burrowed, the sharks used extra behaviors:
- They leveraged their bodies, using pectoral fins for support.
They performed headstands or pulled with their whole bodies to remove stuck food.
- They used their mouths to form a seal over burrowed food for better suction.
- They leveraged their bodies, using pectoral fins for support.
3. No Modulation in Kinematics
- The sharks showed no significant change in jaw opening size, timing, or upper jaw protrusion when prey was harder to access.
- This means they did not “modulate” their basic feeding mechanics; instead, they adapted after the initial bite using body movements.
Why It Matters
- Uses specialized suction feeding, like other bottom-dwelling sharks.
- Has unique behaviors like using its body as a lever and protruding its upper jaw like a chisel to help loosen prey.
- Demonstrates individual variation, but overall does not change its initial suction strike based on prey position.
Horn Shark Study Conclusion
The horn shark is well-adapted to feeding on prey that may be hidden or stuck to rocks on the ocean floor. Its combination of suction feeding and creative body movements makes it an effective hunter in its environment.
Read the full study here.
Article written by: Greer Jessie, B.S. in Biology with an Anthropology Minor, 2025 College Graduate, University of Florida, and Shark Angels intern.