14 of the most interesting shark questions are answered underneath. This article covers the following questions:
- Are Shark Fish?
- What Is The Largest Shark?
- What Is The Smallest Shark?
- Are Sharks Cold Blooded?
- What Do Sharks Eat?
- How Fast Do Sharks Swim?
- How Long Have Sharks Been Around
- How Do Sharks Communicate?
- Do Sharks Get Sick?
- Are Sharks Mammals?
- Do Sharks Have Bones?
- Do Sharks Sleep?
- Do Sharks Have Tongues?
- Do Sharks Lay Eggs?
1. Are Shark Fish?
Yes. Sharks live underwater and breathe through gills. They are generally considered to be cold-blooded.
2. What Is The Largest Shark?
The largest living shark is the Whale Shark, which is over 45 feet, or almost 14 metres, long! Despite being so huge, this shark is harmless to humans as its diet consists solely of plankton and the tiny fish that can get through the feeding sieve in its mammoth mouth.
3. What Is The Smallest Shark?
The smallest shark is the Dwarf Lantern Shark. This shark only reaches a maximum length of 20 cm (7.8 inches) and the largest known individual Dwarf Lantern Shark is 21.2 cm (8.3 inches) long. A shark this small fits in the palm of your hand! This tiny shark is known to reach maturity at a very small size, with the smallest living shark being a male at 16-17.5 cm (6.3 – 6.9 inches). The smallest female shark was around 15.5 cm (6.1 inches) and with the longest known up to 20 cm (7.8 inches).
4. Are Sharks Cold Blooded?
Yes, most sharks are technically cold blooded, or ectothermic. This means that the temperature of their body depends entirely on the temperature of the water around them. But, there are some exceptions to this rule. For example, the Great White Shark controls its body temperature internally, and maintains a warmer temperature than that of its environment. This makes it somewhat warm-blooded, despite not being a true endotherm.
5. What Do Sharks Eat?
Sharks are carnivores. The eat flesh. Most of them eat other live animals but some of them eat carrion. In general sharks eat squid, fish, molluscs, other sharks, turtles, crustaceans, porpoises, dolphins rays and seals. Read more about a the diet of a shark here.
Sharks actually eat slightly less than human beings do in terms of percentage compared to their body weight and size. Their livers are filled with oil that is rich in nutrients and vitamins. In times of great shortage, the shark can live for many months without eating, gaining energy solely from this oil. In addition, most shark species are prone to sticking to one type of food, and are prepared to look for that food rather than eating whatever is more easily available.
6. How Fast Do Sharks Swim?
It is a well known myth that sharks are fast swimmers. The speed that a shark can reach depends very much on what type of shark it is. Most shark species cruise at a slow speed of about nine kilometres an hour. Sharks only speed up when they are in pursuit of prey, as this uses up much of their energy. Some sharks can reach up to 50 kilometres an hour and there have been unconfirmed reports of tracking a shark at nearly 100 kilometres an hour.
7. How Long Have Sharks Been Around?
The evolution of sharks dates back 450 million years ago according to dental remains of ancient sharks. It is difficult to confirm this as the cartilaginous skeleton decomposes upon death, unlike bone, which can stay preserved under optimal conditions for millennia. So, teeth are the only remnants of these now-extinct species. Read more about the evolution of sharks here.
8. How Do Sharks Communicate?
Sharks use their body language for communication with each other. For example, when issuing a warning, the shark will hunch its back and swim with overly-pronounced movements. Surfers and divers that have been attacked have also reported this behaviour prior to the attack.
9. Do Sharks Get Sick?
Yes, they do. Sharks can get bacterial infections, parasites (e.g. tapeworm), liver disease, cancer, meningitis, and even leech and lice infestations. It is a myth that sharks don’t get cancer.
10. Are Sharks Mammals?
No, sharks are not mammals. Let’s define what a mammal is. A mammal is a a warm blooded vertebrate animal and young are nourished with milk from mammary glands from the mother. Typically they birth to live young.
So why aren’t sharks mammals? First of all sharks are cold blooded. They also don’t produce milk for their young. Only a few sharks (viviparous sharks) give birth to live young. A shark is a fish and not a mammal.
11. Do Sharks Have Bones?
No, a shark is made out of cartilage and connective tissue and muscle unlike terrestrial humans, animals, and even other marine animals. So no, sharks have no bones.
12. Do Sharks Sleep?
Not really, sharks don’t sleep like humans. They have restful periods to recover. This period of rest can be considered sleeping but their eyes have to stay open. Sharks stay stationary during periods of rest but they don’t go ‘offline’ like humans do.
13. Do Sharks Have Tongues?
Yes, sharks have tongues but they are referred to as a basihyal. A shark tongue is a piece of cartilage in the same location as a tongue in a human mouth.
14. Do Sharks Lay Eggs?
Yes, some shark do lay eggs. But 70% of sharks are viviparous. This means they give birth to live young. Other sharks are oviparous (they lay eggs) and some sharks are asexual.