As someone who saw the movie “Jaws” at exactly the wrong age, I personally dread being eaten by a shark whenever I swim in the Connecticut River. If only I had seen a nature documentary about the mysteries of the whale shark instead…
Despite my irrational fear (is there any other kind?), I sometimes wish my boy had teeth like a shark. I don't mean that I wish they were terrifyingly large and sharp like a great white's, (Carcharodon carcharias), but the shark's ability to continually replace new teeth as needed, would spare my child pain and save me some money.
And unlike me, a shark has never had to sit in a dentist's chair to have a tooth removed, which I have experienced twice.
Of course, the solution for dental bills and unpleasant dental procedures, is preventative dental care. Avoiding sugary drinks, along with tooth brushing and flossing, is essential.
But it's hard not to be jealous of the shark's superpower. For example, as can be seen in this Smithsonian magazine video, youtube.com/watch?v=_OdsFySWI-k, the great white shark can grow many thousands of teeth, replacing damaged or lost ones whenever it needs to. (Parental warning: This video features the attack of a great white on a seal, which some children will find disturbing.)
A great white shark eats nothing but meat, and their sharp, pointed and triangular slicing teeth are perfectly suited to this diet. Your child grows teeth suitable for biting into and breaking up a wide variety of foods into digestible bits and has a different-shaped tooth for each task.
A somewhat simplified description of the different types of teeth in the human mouth are incisors, canines and molars. Incisors are for tearing off a piece of food, like a hunk of apple. Canines (also called cuspids) are used to tear and rip apart tougher food.
Though we commonly associate canines with wolves and other predators, our vegetarian primate cousins, the gorillas, have enormous canines, despite the lack of meat in their diet.
Molars are used for breaking food down into smaller bits, which makes any food easier to digest. Basically, the smaller an object is, the more surface area it has in comparison to its mass.
This means tiny bits of food are exposed to more digestive acid in your stomach than larger pieces of food. Tiny bits dissolve more quickly and more completely. Chew well.
Another advantage sharks have over humans in the dental department is that, unlike your child, young sharks enter the world with a set of teeth. Not having any alternative to preying upon other fish since their mother's don't produce milk for them to drink, a baby shark needs its teeth shortly after it begins to swim in the ocean.
While nursing babies need no teeth, the delay in dental completeness comes at a price. Human teeth push through their gums as they emerge. This, of course, can be very painful for the babies, who don't know why they are hurting, only that they are in great pain.
Because we are hard-wired to find babies' screams extremely important sounds, teething can also be a hard time for exhausted parents. In contrast, if a shark heard its babies crying, it probably would not feel distress. Who knows, it might use the sounds as a way to hunt for a meal.
Not all sharks need to tear through chunks of flesh. For example, some angel sharks feed on clams. To get at the clam inside the shell, the angel shark needs teeth that can grind down and crack it open. These sharks have teeth which provide the same function as the molars.
Some sharks, such as whale sharks, filter out tiny organisms from the ocean water and don't use their tiny teeth for chewing or tearing at all. In fact, no one knows yet what a whale shark uses their teeth for. That will take more scientific inquiry.
Maybe your child will be the one who cracks that mystery, or maybe it will be a mystery forever.
Rolf Parker received a master’s degree in entomology from Clemson University and lives with his wife, Cynthia Houghton, and their son in Brattleboro. He is a freelance writer and math tutor. He travels to schools and libraries to talk about science, global warming and tree planting. You can see what else he and his wife are up to at greenmountainartifacts.com.