By Blaise Jones
Sharks have some of the most amazing mouths in the animal kingdom. Powerful, versatile, and armed to the literal teeth. In previous articles we sunk our teeth into the various specializations that make these chompers unique for each species, but there is one universally shared trait amongst all these shark’s teeth: they never run out.
Row, Row, Rows of Teeth…
While most toothed animals only have one row of teeth, sharks have multiple. Some species of shark can have as many as eight visible rows of teeth at a time. However only the teeth in the front two rows are functional. The back rows are there as ready replacements, waiting for the tooth in front of it to inevitably fall out.
Meet the New Tooth, Same as the Old Tooth
Even if a shark were to somehow go through its entire life without biting anything, its teeth would still fall out. That’s because shark jaws are designed like a conveyer belt. There are several rows of smaller teeth beneath the gums of the shark. These teeth push forward as they grow, pushing the larger teeth in front of them out of the way. The largest teeth in the front eventually fall out and the tooth behind it takes its place. Depending upon the species a new tooth can go from first growth to front row in as little as two weeks.
Rates of Regeneration
The rate this occurs depends upon several factors. Younger sharks lose their teeth faster than older sharks. Sharks in colder climates tend to lose their teeth slower than sharks in warmer waters. More active sharks lose their teeth faster than the stationary species. Most sharks lose their teeth one at a time, while others lose multiple. For example, when it’s time for the cookiecutter shark to replace its teeth it sheds an entire jaw-worth of teeth at time.
So, How many Teeth Does a Shark Lose in its Lifetime?
The amount of teeth a shark can lose over its lifetime does depend upon the species. The sharks that have several hundred teeth in their jaws will lose more teeth overall than the sharks that only have a dozen teeth. On average, a shark can lose as many as 20,000 – 30,000 teeth over the course of their lifetime.
- “Sharks! The Mysterious Killers” by Downs Matthews
- “Sharks: The Animal Answer Guide” by Gene Helfman and George H. Burgess