The Tiny Fish That Swims Into Sharks’ Mouths to Clean Them

At the bottom of the ocean lives an extraordinary creature that freely swims into the mouths of sharks several times larger and more dangerous than itself. Most astonishingly, sharks do not hunt it—instead, they let it “work.”

These are cleaner wrasses, or cleaner fish. Although their bodies are small, their role in the ocean ecosystem is extremely important.

These tiny fish enter the mouths of sharks and other predatory marine animals, removing food particles stuck between their teeth, parasites, and various small bits of debris. For this reason, they can aptly be called the “dentists” of the ocean.

Normally, a small fish entering a shark’s mouth would be easy prey. But the relationship with cleaner fish is completely different. Predators recognize them and allow the cleaning process to take place. As a result, both sides benefit: the fish finds food, while the shark gets rid of parasites and debris.

Interestingly, this kind of “partnership” is not limited to sharks. Cleaner fish can also provide their services to other large marine animals.