Sharks are among the oldest and most successful animals on Earth, having evolved for over 400 million years. They are also among the most diverse and adaptable, with over 500 species ranging from the tiny dwarf lantern shark to the massive whale shark. But what makes sharks so different from other fish? One of the most distinctive features of sharks is their skeleton, which is not made of bones but of cartilage.
How Many Bones Does a Shark Have or Cartilage
In this article, we will explore how many bones a shark has, or rather, how many cartilages a shark has, and why this gives them an advantage in the aquatic world.
The Short Answer: Sharks Have No Bones
That’s right, sharks do not have any bones in their body. Instead, they have a skeleton made of cartilage, which is a flexible and lightweight tissue that also forms the ears and nose of humans. Cartilage is about half the density of bone, which helps sharks to stay buoyant and swim faster in the water. Cartilage also does not fossilize as easily as bone, which is why there are not many ancient shark fossils available for study.
The Long Answer: Sharks Have Different Types of Cartilage
Although sharks do not have bones, they do have different types of cartilage that serve different functions in their body. According to Wikipedia, the main types of cartilage in sharks are:
- Hyaline cartilage: This is the most common type of cartilage, which forms the basic structure of the shark’s skeleton. It is covered by a layer of mineralized blocks called tesserae, which provide strength and protection to the cartilage.
- Elastic cartilage: This type of cartilage is more flexible and elastic than hyaline cartilage, and it forms the shark’s fins, which help them to steer and lift themselves in the water.
- Fibrocartilage: This type of cartilage is more dense and tough than hyaline cartilage, and it forms the shark’s jaws, which enable them to bite and crush their prey.
How Many Pieces of Cartilage Does a Shark Have?
The number of pieces of cartilage that a shark has depends on the species and size of the shark. However, according to Jacks Of Science, most sharks have between 360-410 pieces of cartilage in their body. These include:
- Vertebrae: These are the segments of cartilage that form the shark’s spine, which supports the body and protects its nerve cord. Sharks have between 80-200 vertebrae, depending on the species and length of the shark.
- Ribs: These are the curved pieces of cartilage that attach to the vertebrae and protect the shark’s internal organs. Sharks have between 40-80 ribs, depending on the species and width of the shark.
- Fins: These are the appendages of cartilage that extend from the shark’s body and help them to swim and balance. Most sharks have eight fins: a pair of pectoral fins, a pair of pelvic fins, two dorsal fins, an anal fin, and a caudal fin (tail).
- Skull: This is the complex structure of cartilage that forms the shark’s head, which houses its brain, eyes, nostrils, mouth, teeth, and gills. The skull consists of several parts, such as the cranium, rostrum, jaws, hyoid arch, branchial arches, and basihyal.
Conclusion
Sharks are amazing animals that have no bones in their body. Instead, they have a skeleton made of cartilage, which is a flexible and lightweight tissue that helps them to swim faster and stay buoyant. Sharks have different types of cartilage that form their vertebrae, ribs, fins, skull, and other parts of their body. Sharks also have teeth made of enamel, which are constantly replaced throughout their life.
We hope you enjoyed this article and learned something new about sharks and their anatomy. If you have any questions or comments, please feel free to share them below.
Most Asked Questions About Shark Bones
Here are some common questions that people have about shark bones and their answers:
- Are shark teeth bone or cartilage? Shark teeth are neither bone nor cartilage; they are made of a hard mineral called enamel, which covers a core of dentin. Shark teeth are constantly replaced throughout their life, as they lose or break them while feeding.
- Are sharks mammals? No, sharks are not mammals; they are fish. However, some sharks give birth to live young (viviparous), while others lay eggs (oviparous). Viviparous sharks develop a placental connection to their mother, similar to mammals.
- What do sharks eat? Sharks eat a variety of prey, depending on their species and size. Most sharks eat small fish and invertebrates, while larger sharks eat seals, sea lions, dolphins, turtles, and other marine mammals. Sharks do not actively hunt humans; most attacks are due to confusion or curiosity.
- How many species of sharks are there? There are over 500 species of sharks in the world, ranging from the tiny dwarf lantern shark (about 8 inches long) to the massive whale shark (about 40 feet long). Some of the most well-known species include great white sharks, tiger sharks, hammerhead sharks, mako sharks, bull sharks, blue sharks, lemon sharks, nurse sharks, and reef sharks.
- How old are sharks? Sharks are among the oldest living animals on Earth, with their ancestors dating back to about 455 million years ago, according to NOAA. Sharks have evolved and adapted to various environmental changes over time, making them successful survivors.
- How fast can sharks swim? Sharks can swim at different speeds, depending on their species and situation. Some of the fastest sharks include the shortfin mako shark (up to 60 mph), the blue shark (up to 43 mph), and the great white shark (up to 35 mph). However, most sharks swim at an average speed of 5 mph.
- How long can sharks live? Sharks can live for different lengths of time, depending on their species and environment. Some of the longest-lived sharks include the Greenland shark (up to 400 years), the bowhead whale shark (up to 130 years), and the spiny dogfish shark (up to 100 years). However, most sharks live for 20-30 years.
- How do sharks breathe? Sharks breathe by taking in water through their mouth or nostrils and passing it over their gills, which extract oxygen from the water and expel carbon dioxide. Some sharks have to keep swimming to maintain a constant flow of water over their gills, while others can pump water over their gills by opening and closing their mouth.
- How do sharks sense their prey? Sharks have a keen sense of smell, hearing, vision, taste, and touch, which help them to locate and identify their prey. However, they also have a unique sense called electroreception, which allows them to detect the weak electric fields generated by living organisms. Sharks have special organs called ampullae of Lorenzini, which are pores filled with gel that connect to nerve endings in their snout. These organs help sharks to sense the heartbeat, muscle movement, and nerve impulses of their prey, even in murky water or darkness.
- How do sharks communicate? Sharks communicate with each other using body language, sounds, smells, and bioluminescence. They use different postures, movements, and gestures to convey messages such as aggression, submission, courtship, or curiosity. They also make sounds such as clicks, grunts, snaps, or thumps to attract mates or warn off rivals. They release chemicals called pheromones, which can influence the behavior or mood of other sharks. Some sharks can also produce light from special cells called photophores, which can help them to camouflage, lure prey, or signal to others.