How the Bonnethead Shark Sees Its World & Why It Matters for Conservation
Bonnethead shark swimming over stingray
Seeing the Ocean in Color
When most people picture sharks, they imagine sleek predators cruising through blue-gray water - powerful, focused, and color-blind. But one small hammerhead species breaks the mold.
Meet the bonnethead shark (Sphyrna tiburo), the only known shark with true color vision!
That might not sound groundbreaking at first, but in the world of marine biology, it’s a remarkable discovery. Most sharks see in shades of blue and gray, their retinas packed with rod cells optimized for dim, deep-water vision. Bonnetheads, however, have cone cells - the same light-sensitive cells humans use to perceive color.
According to research published by McComb et al. (2009, Journal of Experimental Biology), bonnetheads and other hammerheads exhibit unique visual adaptations that enhance their field of view and depth perception. Later studies (Florida Atlantic University, 2010) confirmed that these sharks have multiple cone types, suggesting they can detect a spectrum of colors in bright, shallow water.
Close-up of bonnethead eye over seagrass background
Why Color Vision Matters
Bonnetheads spend their lives in Florida’s shallow, seagrass-rich estuaries, where sunlight filters through clear water. Being able to see in color likely helps them:
Distinguish prey like crabs and shrimp from seagrass blades
Identify healthy habitats based on color and contrast cues
Navigate the complex mosaic of coastal nurseries
This adaptation gives bonnetheads an edge in dynamic, light-filled environments where most sharks would see little more than shadows.
Color vision could even help them locate nutrient-rich seagrass, which they occasionally snack on. Bonnetheads are the first known omnivorous sharks, eating both crustaceans and plants, making them ecological bridge builders between predator and grazer.
Seagrass meadow beneath the surface, sunlight streaming through water
What It Reveals About Coastal Health
Understanding how bonnetheads see their world also helps scientists monitor the health of Florida’s estuaries.
Their reliance on sight means bonnetheads are highly sensitive to water clarity and turbidity - both affected by urban runoff and pollution. Studying their visual behavior can reveal how human activity influences not just shark survival, but the stability of entire seagrass ecosystems.
At The Salty Lab, our upcoming Project One builds on this foundation and connects bonnethead physiology, habitat quality, and coastal management to guide better policy decisions for Florida’s blue heart.
Map of Florida estuary - Biscayne Bay
Conservation Through Understanding
The more we uncover about bonnetheads, the more they redefine what it means to be a shark. Far from mindless hunters, they are sentinels of coastal change - small but vital players in a delicate balance between science, habitat, and humanity.
By translating discoveries like these into education, outreach, and conservation, we can help ensure these sharks — and the seagrass meadows they depend on - continue to thrive.
Want to explore the science behind The Salty Lab’s fieldwork?
👉 Check out Project One and our latest conservation gear at The Salty Lab Shop. Every purchase fuels real research and restoration.
Sources & Further Reading
McComb, D. M., Tricas, T. C., & Kajiura, S. M. (2009). Enhanced visual fields in hammerhead sharks. Journal of Experimental Biology, 212(24), 4010-4018. Read study
McComb, D. M. et al. (2010). Spectral sensitivity in elasmobranchs. Florida Atlantic University PDF
Kennedy, J. (2019). Bonnethead Shark Science. ThoughtCo
NOAA Fisheries. (2025). Bonnethead Shark: Science. NOAA.gov
