No, That's NOT a Baby Hammerhead

One of the most common things we educators have heard while speaking with visitors at The Trust Family Foundation Shark and Ray Touch Tank is requests to touch the baby hammerhead shark. This is pretty much what we expected when we added one of our favorite animals to the new exhibit. But those sharks everyone asks about are actually called bonnethead sharks!

Bonnethead shark in The Trust Family Foundation Shark and Ray Touch Tank, photo credit: Keith Ellenbogen

Bonnethead sharks (Sphyrna tiburo) are in the hammerhead shark family, but deserve recognition of their own. They are the smallest species of that family, and their heads are shaped much more rounded than the stereotypical, more rectangular hammerhead shape. In all hammerhead species, this unique head shape is known as a cephalofoil. They sway this cephalofoil back and forth as they swim, using their very sensitive sensory and nervous systems to locate prey.

Hammerhead shark, photo courtesy: Barry Peters via Wikimedia Commons

Perhaps the most fascinating fact about bonnethead sharks is that they have been documented to reproduce asexually. In 2001, a female bonnethead at the Henry Doorly Zoo in Nebraska who had never had contact with a male gave birth to a pup. Genetic testing confirmed that the pup was identical genetically to its mother. This type of reproduction, previously unknown in cartilaginous fishes like sharks and rays, is known as parthenogenesis.

Photo credit: Keith Ellenbogen

The new touch tank is a great place for these sharks, since they are naturally found in coastal waters on both sides of the Americas. While they have been spotted rarely in New England waters, they prefer water temperatures above 70 degrees F.

So next time you’re at The Trust Family Foundation Shark and Ray Touch Tank, ask the educator on duty about the bonnethead shark. We love to teach visitors that they're not just another hammerhead!