Sharks, do not have any bones. That doesn't imply they're as floppy as a jellyfish, though. They are categorised as vertebrates since they still have strong skeletons. Sharks have cartilage instead of hard bones like other animals.
Cartilage is a softer, more flexible tissue than bone that can yet hold muscle and skin in place. It’s the same substance that accumulates in your ears and nose. It’s also why newborns’ bodies are so flexible. Humans begin with cartilage, which gradually rigidify as our bones expand. Sharks are able to swim quickly through the water because of their flexibility, as well as twist and shake their prey once hooked.
If Not Bones What Does Sharks Have?
We already know that sharks have no bones and just cartilages, but the amount of cartilage is difficult to determine because it is basically just some connective tissue. It is, however, simpler to determine where a shark has cartilage, as this will impact the amount of pliable material present. A shark’s spine, fins, skull, and jaw are all made out of cartilage. As a result, because larger sharks have larger bodies to fill, they will have more cartilage than smaller sharks. Sharks do not have rib cages, even those composed of cartilage.
Why Don't Sharks Have Bones?
The absence of bones in sharks’ skeleton might be for a variety of reasons. There is a theory that the present shark’s forebears had bones hundreds of years ago. Many shark species have evolved throughout time to better adapt to their environments. As a result, they appear to have evolved into cartilaginous fish.
Sharks evolved into the fearsome predators that they are today as a result of this development. They wouldn’t be able to dodge their own predators as quickly if they didn’t have their lightweight, flexible skeletons.
They wouldn’t be as fast swimmers, and they wouldn’t be able to grab their prey as swiftly and smoothly as they do.
Sharks aren’t the only animals with cartilage instead of bones in their bodies. Stingrays, manta rays, and sawfish are examples of cartilaginous fish. Elasmobranchs are another name for this type of fish.
Chimaeras are a kind of cartilaginous fish that has evolved throughout time. These are shark, ray, and sawfish relatives. The various ghost shark species, the spookfish, and the rabbitfish are examples of chimaera fish.
Invertebrates such as jellyfish, octopus, and shrimp likewise lack bones. That is to say, they have no backbone.