Are Sharks and Rays Bony Fish?
We often hear of sharks and rays when we think of fish, but are they actually bony fish? The answer is not as straightforward as it may seem.
Sharks and rays are not actually ‘bony fish’ but they are classed as ‘cartilaginous fish’. This group includes sharks, rays, skates and chimaeras. They are so-called because their skeletons are made of cartilage and not bone. Cartilage is a connective tissue which is found in the bodies of all vertebrates, including humans. It is softer and more flexible than bone and allows for greater manoeuvrability in the water.
What is the Difference Between Bony Fish and Cartilaginous Fish?
The main difference between bony fish and cartilaginous fish is the composition of their skeletons. Bony fish have skeletons made of hard, mineralized bone, while cartilaginous fish have skeletons made of cartilage. This difference affects the way in which the fish move in the water. Bony fish have rigid skeletons that are not as flexible as cartilaginous fish, so they cannot make the same sharp turns and flexible movements that cartilaginous fish can.
What are the Characteristics of Sharks and Rays?
Sharks and rays have a number of characteristics that make them distinct from bony fish. They have a streamlined body shape which helps them to move quickly and efficiently through the water. They also have a number of specialised adaptations for feeding, such as sharp, pointed teeth, and an enlarged jaw which allows them to take large prey. Sharks and rays also have skin that is covered in dermal denticles, which are small, tooth-like structures that help to reduce drag in the water.
What are the Advantages of Being a Cartilaginous Fish?
The main advantage of being a cartilaginous fish is that they have a more flexible skeleton which allows them to move more quickly and efficiently through the water. This makes them well-suited to hunting large prey and escaping predators. Cartilaginous fish also have an additional layer of protection due to their ‘placoid scales’, which are small, tooth-like structures that cover their bodies. This helps to protect them from injury and also reduces drag in the water.
What Types of Cartilaginous Fish are Found in the Ocean?
There are two main types of cartilaginous fish: sharks and rays. Sharks are the most well-known cartilaginous fish and include species such as the great white shark, tiger shark, and hammerhead shark. Rays are flattened cartilaginous fish which have a disc-like body and include species such as the manta ray and the stingray.
Are Sharks and Rays Endangered?
Unfortunately, many species of sharks and rays are threatened by overfishing and other human activities. As a result, a number of species are now considered to be endangered or vulnerable. It is important that we work to protect these species and their habitats in order to ensure their long-term survival.
Conclusion
Sharks and rays are not bony fish, but rather cartilaginous fish. They are distinct from bony fish due to their flexible skeletons and specialised adaptations for feeding. They are also threatened by overfishing and other human activities, making it important that we work to protect them and their habitats.