Do sharks have bones? Understanding the body composition of the ocean's apex predator

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Sharks are fascinating creatures. These fish have been around for around 455 million years and are known to be one of the ocean's apex predators, according to the National Oceanic and Atmospheric Administration.

Each species of shark is unique and has its own way of living. For instance, some sharks reproduce in different ways than others, and not all sharks have the same teeth, says NOAA.

But what about a shark's body makeup? Are strong bones the reason sharks are such a strong force in the ocean?

Sharks do not have bones but are made of cartilaginous tissues like other "elasmobranchs," such as rays and skates.
Sharks do not have bones but are made of cartilaginous tissues like other "elasmobranchs," such as rays and skates.

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Do sharks have bones?

No, sharks do not have bones. In fact, sharks are "elasmobranchs," which means they are made of cartilaginous tissues, according to the NOAA. Cartilaginous tissues also make up human's ears and the tips of our noses. 

Rays, sawfish and skates are fellow elasmobranchs. These fish are lighter since cartilage is around half the density of bone, according to Discovery UK. Elasmobranchs do not have swim bladders, which traditionally increase a fish's buoyancy. So, these fishes' low density aids buoyancy and prevents them sinking.

Sharks also have livers filled with low-density oils, which helps them to be buoyant, says the NOAA.

Are sharks jaws made of bone?

Although sharks are not composed of bone, these fish can fossilize.

Dried shark jaws often look as if they are made of bone, but they are not, says the NOAA. As sharks get older, calcium salts are deposited into their skeletal cartilage to strengthen it. These minerals allow most sharks to fossilize nicely.

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Are shark teeth bone or cartilage?

Shark teeth have dentin, like human teeth, according to the Dental Center of Indiana.This is a soft tissue-like material found inside teeth.

Similar to humans, sharks also have hard enamel surrounding their teeth. The enamel of shark teeth shows up in fossil records, says the NOAA.

Shark teeth are also comprised of calcium phosphate, which makes them quite tough, says the Dental Center of Indiana. Certain sharks, like nurse sharks, can crush crabs and other shelled animals in one bite, while others, like bull sharks, chew through fish and squid.

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This article originally appeared on USA TODAY: Do sharks have bones? Facts about the fish's body, jaw and teeth