If you are anything like me, then you spent all of last week glued to the television, watching countless documentaries about our oceans’ apex predators. For those who are not aware of what I am talking about, last week was Discovery Channel’s renowned Shark Week. Devoting an entire week toward the top dogs of the sea, the Discovery Channel informed viewers about almost anything and everything you need to know about sharks. There are more than 465 known species of sharks living in our oceans and are the largest known predators. As I mentioned before, sharks are apex predators meaning that they are at the top of their marine food chains and regulate populations of species below them. As a marine biology student, the forty-some hours spent watching Shark Week was not enough, so here are 23 “jaw-some” shark facts that will have you swimming for more.
1. Almost nothing is older than sharks. Sharks have been swimming in our oceans for more than 400 million years and have survived five mass extinctions that killed off many prehistoric species, such as dinosaurs.
2. Sharks’ livers contain a high amount of oil, making the liver relatively buoyant. This helps sharks keep their balance in the water.
3. A single person consumes approximately half a ton of food each year. In comparison to humans, great white sharks consume nearly 11 tons of food each year.
4. Instead of chewing their prey and using the multiple rows of teeth in their mouth, shark teeth are used for snapping, crushing or ripping the food and then followed by swallowing the chunks whole.
5. Shark skeletons are made completely of cartilage, an elastic tissue that is much softer than bones.
6. Sharks only possess a single type of cone photoreceptor in their retina, meaning they can only view their world in black and white.
7. Depending on the species, a shark's length can range anywhere from seven inches to 50 feet.
8. Sharks are intelligent predators. Nurse sharks found in the Bahamas are known to float right onto docks to feast while Caribbean reef sharks will nearly come onto the beach to find prey.
9. Although they lack cone photoreceptors that limit their vision to black and white, sharks have great night vision due to a membrane in the back of their eye called the Tapetum Lucidium. This membrane makes them more sensitive to light by reflecting sunlight back into the retina.
10. Unlike most types of sharks, whale sharks can carry more than 300 pups at one time.
11. Tiger sharks aid in keeping seagrass beds healthy by preventing turtles from overgrazing.
12. To deter potential predators, baby bamboo sharks can mimic the appearance of poisonous sea snakes.
13. Shark meat contains higher toxic mercury levels than any other fish.
14. The hammerhead sharks are one of the best hunters due to their unique head shape. Their electroreceptors are spread out over a larger surface area, allowing them to detect prey from a greater distance.
15. Due to over-exploitation and lack of proper management, many shark species are at risk of unrecoverable decline.
16. Great white sharks have a life span of 50-plus years and take approximately 12-15 years to reach sexual maturity.
17. The most common shark along the West coast of North America is the leopard shark (Triakis semifasciate).
18. Whale sharks are the largest species of shark, growing over 18 meters in length, but feed mainly on plankton.
19. Many sharks rely on ram ventilation, meaning that they must constantly keep swimming in order to breathe.
20. Sharks have no need to worry about brushing their teeth considering their tooth enamel is made up of a chemical called Fluoroapatite. This chemical coats their teeth and is resistant to acid produced by bacteria.
21. The skin of a female shark is much thicker than that of a male because male sharks bite females during mating.
22. You are more likely to be killed by a falling coconut than a shark. Falling coconuts kill roughly 150 people per year while sharks kill only four-12.
23. In the time it has taken you to read this message, it is predicted that up to 100 sharks will have been killed worldwide, largely to support the shark fin trade.
These marine creatures are nowhere near as harmful as their stereotypes portray them to be. In fact, it is estimated that sharks are being killed as a result of by-catching and shark finning at a rate of 273 million per year. We are a much larger threat to their population than they are to ours. To learn more about the efforts toward saving the shark population or sharks in general, visit the Discovery Channel's Sharkopedia.
