It’s true — stingrays have teeth! But what would you say if we told you that stingray teeth closely resemble human teeth?
Have you ever fed our stingrays in The Shallows? If so, you might’ve glimpsed what appears to be a ridge of teeth but — spoiler alert — those are actually lips! So let’s take a closer look, Magic School Bus style, at the relationship between two important anatomical structures on stingrays: placoid scales and teeth.
Placoid scales are tiny, hard, flattened, tooth-like structures that cover the body of stingrays and have an enamel coating, helping to protect them from predators. Likewise, stingray teeth are made of a special type of placoid scales that are very similar to human teeth. They have a central cavity supplied with blood flow and they’re covered with a layer of dentine (hard tissue). Just like humans, the final layer on the tooth includes an enamel-like substance, too.
Stingray teeth have two edges — one with ridges and one that’s smooth. Fun fact: The smooth part faces outward, not the ridge part!
Stingray teeth form plates inside the stingray’s jaw, making it easier to crush prey.As stingrays forage along the bottom of their habitat looking for crustaceans, shellfish, squid and fish, they use small, modified fin lobes near their mouth opening to direct food inward. Since prey like crustaceans and shellfish have a hard, outer shell, the stingrays need to be able to crush their food thoroughly. Each singular stingray tooth falls into place to create plates on the top and bottom of the stingray’s mouth. The plates of teeth work together to grind food back and forth, making it easier to digest.
Also similar to humans, stingrays can lose their teeth! Each time our team cleans The Shallows, they remove fallen teeth from the bottom of the tank. Unlike humans though, losing teeth into adulthood is completely normal for a stingray, and a new tooth always replace the old one!
The next time you visit the Aquarium, make sure to stop at The Shallows and ask an educator to see some stingray teeth! If you have additional time, take a walk along the Charleston Harbor. Who knows? You may spot the fevers of cownose rays that have been gracing our waters as of late!
This stingray jaw shows the placement of the teeth, forming plates used to crush its food.A special thank you to our expert, Angela Zepp, dive operations team member, for her time and knowledge in creating this blog.
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Published July 11, 2022