Do Sharks Have Cartilage: What Kind, Why, Several Facts


Sharks are apex marine predators, which might give us the impression of their mighty and strong bony bodies. But there’s a catch- sharks do not have bones. We mean it!

The skeletal system of a shark, on the other hand, is constructed entirely of cartilage. These fish are called “elasmobranchs,” which means “fish with cartilaginous tissues.” As a result, their entire body comprises a more elastic and flexible alternative to bones, making them much lighter and aiding in buoyancy.

Do Sharks Have Cartilage
Image Credit: Shark’s dangerous jaws from Pxhere

Even when sharks do not have bones, it will be a mistake to consider them fragile. In fact, they are one of the most vicious marine creatures and belong to the top category of predators in the food chain. 

Your fascination won’t end here, as there are many more things to these fishes than are seen with naked eyes. We are also sure that your head is churning out several questions regarding how, why, and what. And to answer all those questions, we have presented an informative post here. This post will deal with several fascinating facts about sharks’ cartilaginous bodies. 

So, stay with us to learn about sharks’ bodies and skeletal structures. 

Do sharks have cartilage instead of bones?

Sharks have often been depicted as sneering, ferocious ocean predators. But there is more than that to sharks- their specially evolved body.

Sharks have cartilage in place of bones in their bodies. Human bodies, including the nose, ears, and bone joints, also include cartilage. Shark cartilage, on the other hand, is not as supple. In reality, the calcification process makes their cartilaginous body as strong as any living entity with a bony skeleton.

It is, however, not only sharks that have this skeleton. Ocean creatures like rays, skates, and chimaeras also possess cartilaginous skeletons. A cartilaginous body makes a shark lighter, enabling them to travel faster through the water without much effort.

Why do sharks have cartilage?

A shark’s body is made up of various types of tissue, one of which is cartilage. So the first question that comes to mind is why these fish have cartilage rather than bones.

The answer is simple: a shark’s cartilaginous body is required to survive. The cartilaginous bodies of these fishes have evolved so that they can swim faster and with more agility. It also aids their bodies in carrying their tremendous weight and allows them to move more freely.

The fact that cartilage has a low density may fascinate you. As a result, a shark’s body mass is lowered dramatically, making it easier for them to move through the water.

Sharks also don’t have a swimming bladder. As a result, they rely on their cartilaginous bodies to conserve energy when swimming. So, we can say that sharks are fortunate to have cartilage rather than bones in their skeletal system in many respects.

Advantaged and disadvantages of having cartilage instead of bones

Image Credit: Sharks are cartilaginous fishes from Pxhere

By now, you are well aware that sharks are happy to have cartilaginous bodies. Here is a list of advantages and disadvantages of this kind of skeletal system.

Advantages:

  • Flexibility:

Cartilage is extremely elastic, giving a shark’s body amazing flexibility. Sharks benefit from this flexibility since it allows them to be better hunters and swimmers.

  • Weight reduction:

Despite its density, cartilage is not as weighty as bones. As a result, sharks’ weight is reduced, making it easier for them to swim quicker. In addition, they can hunt better with a lightweight body and save themselves from potential predators by moving swiftly.

  • Better healing:

Cartilage is known to have better healing properties. Hence, even if sharks get injured, nothing becomes severe in their case.

  • Buoyancy:

Cartilage is lighter than bones and thus more buoyant. A shark does not use swim bladders to sustain neutral buoyancy because cartilage maintains its capacity to float.

Because of flexible cartilage, sharks can open and stretch their jaws outside while searching and catching prey. This mechanism uses less energy and benefits them from catching their prey from a greater distance.

Disadvantages:

  • More injuries:

Although cartilage aids in rapid healing, it also increases the risk of damage. Sharks are more likely to be injured because cartilage is softer than bone.

  • Less prone to fossilize:

Cartilages are not calcified, which restricts them from getting fossilized. The same can be stated for sharks as well. However, since sharks’ teeth and vertebra are the most calcified cartilage in their body, scientists have to depend on these parts to study them. 

What kind of cartilage do sharks have?

Sharks benefit from cartilage in various ways, like, it aids sharks in becoming the apex predators that they are today.

The skeletal system of a modern shark is built up of prismatic calcified cartilage tissue. In other words, the cartilaginous skeleton of sharks is mineralized as a patchwork of tiny mineral prisms rather than solid sheets.

Gogo sharks, a species with an early form of prismatic calcified cartilage, are fascinating to study. These sharks have a cartilaginous body with prisms that contain cells that look like bone cells.

This discovery suggests that the placoderms, the oldest and most primitive of all jawed vertebrates, may have had massive bony skeletons. And it is from them that modern cartilaginous sharks have evolved.

Do shark fins have cartilage?

Image Credit: A shark’s fin on the water surface from Maxpixel

Sharks are magnificent creature that has existed for hundreds of millions of years. However, they are highly unique when it comes to body shape and composting material.

That said, sharks’ fins are made out of calcified cartilage. Sharks have a huge dorsal fin that aids in maintaining balance in the water. Smaller dorsal and pectoral fins let these fish navigate and elevate themselves in the water.

Shark fins are interesting and are both a benefit and a disadvantage because most sharks are killed just for their fins.

Do shark vertebrae contain cartilage?

So, this is true that modern-day sharks do not contain any true bone in their body. Instead, all of their building blocks are cartilaginous.

Sharks’ vertebrae are also composed of nothing but cartilage. The cartilaginous vertebrae of sharks make them far more flexible and provide enough spinal support. Furthermore, the cartilage of the shark vertebrae is sufficiently hardened to provide optimal strength and durability.

The calcification of a shark’s spine is responsible for its ability to move fast in the water. Water, minerals, proteoglycan, and protein make up the cartilaginous vertebrae of sharks.

Are sharks’ jaws composed of cartilage?

Image Credit: A shark grabbing prey from Maxpixel

Sharks’ jaws are one of the fascinating features. Sharks have numerous layers of teeth in their retractable jaws. And yes, they grow and regrow hundreds and thousands of teeth.

Shark jaws comprise cartilage, just like the rest of their bodies. Tesserae, calcium blocks, provide immense support to shark jaws. This tessera is due to which shark jaws have extraordinary strength and flexibility.  

It’s worth noting that there’s only one row of tesserae blocks in most sharks. On the other hand, larger shark species may contain up to five layers of tesserae.

Keep in mind that, although comprised of cartilage, shark jaws are extremely strong, capable of grabbing and ripping prey apart in a single bite.

Is the cartilaginous body of a shark soft?

Sharks are one-of-a-kind, fearsomely large fish. They can easily grab prey and exert a massive force with their jaws. But doesn’t their cartilaginous body make them weak?

Sharks have a cartilaginous skeletal system, yet they are not soft fish. It’s worthwhile to note that the majority of a shark’s skeleton is calcified. So, they get a much stronger body that is no less efficient in hunting than a body composed of bones. 

We may obtain a good idea of a shark’s strength by looking at its biting force (1.8 tonnes), which is more than three times that of a huge lion.

In this regard, the extinct shark species of Megalodon, the monster of the ocean, had the most powerful bite of any animal.

Do sharks’ cartilaginous bodies fossilize?

Cartilage is softer than bones and does not fossilize due to its lack of mineralization. Is it possible to say the same thing about sharks?

Sharks do not have bones, yet certain sections of their skeletal system are mineralized enough to allow them to fossilize. The teeth, jaw, and vertebrae of sharks are the most typically encountered fossils in this context. These are the only sources of information about these fishes and their predecessors that scientists have.

It’s interesting to note that a shark’s dry jaw might appear to be as powerful as a bony jaw due to calcification. And it is due to calcification that shark jaws become fossilized. But, on the other hand, the teeth have enamel-like substances, which helps them get fossilized. 

Summary

To sum up, while sharks have a cartilaginous body, they are far from being soft fishes. So, please do not go by their anatomy; they are and will continue to be the ocean’s top predators for a long time. With that in mind, we hope you enjoyed our post and learned some interesting information about sharks’ cartilaginous skeletal structure.

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