Bonnethead Sharks or Sphyrna tiburo are the smallest member of the hammerhead family that can reach up to 4 feet long. They are an amazing indication here in the low country that summer has arrived! The once quiet salt marsh is now full of bonnethead sharks that can be found feeding on a variety of crustaceans and small fish during low tide near the exposed mudflats. Although these sharks are mostly carnivorous, they occasionally eat plants such as seaweed or seagrass making them omnivores unlike their other hammerhead family members.
But, just like other hammerhead sharks, the bonnethead shark has an odd, shaped head that distinguishes them from other shark species. They have a unique shovel shaped head that allows them to make sharper turns and have a wider range of vision when hunting for prey. Not only are their heads different than other shark species, but they are the only known species of shark in the world that you can distinguish females from males based on their heads. Female bonnethead sharks have a smooth round head compared to the males who have a bulge on their head. Recent research has also suggested bonnethead sharks are sensitive to the earth’s magnetic field and likely utilize it during migration to navigate from deep waters in the winter to shallower waters in the summer.
Like dolphins, these sharks also travel in groups of up to 15 but have been seen in the thousands during migration! Bonnethead sharks also excrete cerebrospinal fluid that informs other sharks nearby of their arrival. Bonnethead sharks are a unique and amazing animal that has been listed as an endangered species since 2019 due to overfishing by small scale fisheries. To see these awesome sharks in person join us on a guided boat or kayak tour or enjoy them on your own adventure by renting a kayak or paddleboard!
Post by Ally Jo Salomon (Naturalist Guide)