Sharks are like dogs. There are big ones, little ones, brown ones, fuzzy ones. Except, you might not have as much luck cuddling with them. There are lots of features on sharks that you might have seen just from looking at pictures of them, or watching movies. But these little things that might seem boring, like their different colors, might actually have special stories behind them. Even though it’s right in front of your face, you might never notice it.
Cool Camo: Lots of sharks have shading like the great white, with gray on the top and white on the bottom. This is called countershading. Countershading plays a big role in how open ocean sharks hunt and survive. When you look down at the ocean floor from the surface in deep water, all you’d see at the bottom is gray. Now, imagine a shark swimming underneath you. If it was orange, it would be impossible to miss! But a gray shark, you might not even see. Same from the bottom. If you were laying on the ocean floor looking up, there would be light from the surface making the water brighter. A shark with a white bottom would camouflage with that light and might be hard to spot. Countershading is a huge role in how sharks not only hunt, but also hide. Sharks do in fact have predators, and being able to camouflage is just as important to them as it is with any other kind of fish.
Chompers: How are sharks different from normal fish? Well, really there are lots of things. But, one of the most interesting differences is their teeth. Do you have a shark tooth necklace, or maybe have heard stories of people you know finding shark teeth on vacations, like in Hawaii? Sharks are pretty much constantly losing teeth throughout their lives. They can lose up to 30,000 teeth in a lifetime! Imagine losing a tooth every week or so. Probably wouldn’t be very pleasant. The good news for sharks is that they really don’t feel it. Maybe it would feel like a little itch for a few minutes, but there are so many teeth and they fall out so often that they really don’t even notice. All different species of sharks have different shaped teeth too. Some teeth are smaller than your pinky nail and smooth like a black tip reef shark tooth, while some can be almost as big as your hand and serrated, like a goblin shark.
Sharp Skin: Another cool difference between sharks and fish is their skin. Now, fish have scales, just like mermaids. Everyone knows that. But don’t sharks have the same? Not quite. Sharks actually don’t have scales. Instead, they have scale-like things that are shaped kind of like their teeth. These are called dermal denticles. Funnier looking than scales, and have a funnier name too! In fact, these dermal denticles are actually also made from the same thing as their teeth. So, like the teeth, all types of sharks have different shaped dermal denticles. The thickness of this skin layer can vary a lot. Some sharks have skin not much thicker than a fingernail, but others, like the gentle giant whale shark, have skin up to 6 inches thick.
Tippy Tails: Sharks' tails also can be very different, and these different shapes serve different purposes. Then there are some sharks that have kind of crazy tails, such as the Thresher Shark which uses it's tail to hunt. Thresher sharks use their tails to slap the fish they’re trying to catch really hard. When the fish gets slapped, it gets paralyzed, and the shark can just eat it out of the water.