One of my biggest fears when going to the beach is getting mauled by a shark. It’s just a constant fear but of course, we are taught that sharks don’t usually attack humans except for strange circumstances. I’ve read stories about a teen surfer whose arm was bitten off by a shark – or sharks attacking people at the beach on shallow water. Those things I usually try to keep off my mind when I’m in the ocean during the summer months.
As you all know, this is Shark Week 2014 and the Discovery Channel has prepared a lot of good shows for Shark Week followers. The shows have been very successful since its inception in 1988. If you can imagine 26 years since it first started – – that’s an amazing feat!
Anyway, so that you don’t get freaked out the next time you go to the beach, (I’m scheduled to be in Rehoboth Beach, DE for Labor Day Weekend), here are some facts about sharks and why they are important to the ecosystem.
In some form, sharks have been around for about 400 million years. They are the top predators of the ocean’s natural food chain.
Even before dinosaurs roamed the earth, sharks hunted through the oceans! They’re such good survivors that they’ve had little need to evolve in the last 150 million years.
There are over 400 types of sharks — at least 30 of these species have been known to attack humans. They range in size from 6 inches to 45 feet.
These ancient predators fascinate adults and children alike.
Scientific Information: Sharks belong to the class of fish, Chondrichthyes.
Sharks have the most powerful jaws on the planet. Unlike most animals’ jaws, both the sharks’ upper and lower jaws move.
A shark bites with it’s lower jaw first and then its upper. It tosses its head back and forth to tear loose a piece of meat which it swallows whole.
Each type of shark has a different shaped tooth depending on their diet (the shark in the photo is a great white — you can tell he’s a carnivore just by looking at those sharp, pointy teeth!).
A shark may grow and use over 20,000 teeth in its lifetime!
Sharks never run out of teeth. If one is lost, another spins forward from the rows and rows of backup teeth.
Normally, sharks eat alone. But sometimes one feeding shark attracts others. They swim up as quickly as possible and all begin to try to get a piece of the prey. They bite wildly at anything that gets in their way — even each other.
The great white shark rarely partakes in feeding frenzies. One distinctive great white shark “group feeding” episode was witnessed by scientists — a group of great whites shared the carcass of a whale. Rather than the feeding frenzy many types of sharks participate in, the great whites swam calmly around each other “sizing” one another up. They then took turns feeding from the whale carcass in order from the largest great white to the smallest. Scientists were surprised by this orderly and intelligent behaviour!
Almost all sharks are “carnivores” or meat eaters. They live on a diet of fish and sea mammals (like dolphins and seals) and even such prey as turtles and seagulls.
Sharks even eat other sharks. For example, a tiger shark might eat a bull shark, a bull shark might eat a blacktip shark and a blacktip shark might eat a dogfish shark!
The teeth of the carnivores are sharp and pointy. Their skeleton is made of cartilage instead of bone, which allows greater flexibility.
Their skin is made of denticles instead of ordinary fish scales. The denticles are constructed like hard, sharp teeth and help to protect the shark from injury.
Not all sharks are fierce carnivores. Some are quite harmless. Oddly enough, the most harmless sharks tend to be the largest! The basking shark (pictured in the photo), the whale shark and the megamouth sharks all fit this description.
These huge sharks eat plankton, a tiny shrimp-like creature found in the ocean. To do this, they swim forward with their mouths wide open. “Gill rakers” at the back of their throat strain the tiny food from the water.
Think sharks are dangerous? The most dangerous sharks are the Great White shark, the Tiger shark, the Hammerhead shark, the Mako shark and the Bull shark. On average, there are only about 100 shark attacks each year and only 10 of those result in a human death.
You should check it out from their perspective, though! People kill thousands of sharks in a year for sport and for food. Shark skins are used to make products like any other leather would be. Up until the 1950’s, shark livers were used as a vitamin A supplement. Shark fin soup and shark steaks are both eaten in many countries (Mako, seen in the top photo, is the most popular in the United States).
So… Who’s the dangerous predator?