Sharks, along with other members of the elasmobranch family (rays, skates and sawfish) are distinct from bony fish such as trout and salmon in that they lack bone. Instead, these amazing creatures have skeletons made of cartilage which helps them remain one of the fastest and most powerful predators in the world!
Do Sharks Have Ribs?
While sharks have bones, they are classified as vertebrates because they do have a spinal column. This spine is formed from specialized cartilage vertebrae that do the same job as bony vertebrae, providing structure and support but without the weight of traditional bones. This allows sharks to reach incredibly large sizes that would not be possible with heavy, thick-boned skeletons.
As well as protecting the spinal cord, the specialised cartilage vertebrae also help to anchor a shark’s body, reduce drag and allow them to move quickly through the water. It also enables the shark to bend, a vital skill in pursuing prey or evading predators.
The Mystery of Shark Skeletons: Boneless Predators of the Sea
Sharks do have a skull which is again made from cartilage. This supple material is much lighter than bone and allows the jaw to flex, enabling it to penetrate with incredible force.
Wherever you would expect to find bone in a shark, such as their spine, fins and head, you’ll actually find tough, hard cartilage. This is because the sharks have what is known as a calcified cartilage skeleton which, although it lacks the rigidity of bone, still gives them their shape and allows them to cruise the oceans with power and grace.