If there’s one thing that’s generally known about sharks, it’s that they have sharp teeth. But have you heard they have to keep moving to stay alive? Why is that? In this episode we talk to shark scientist Melissa Cristina Marquez about this very question.

Do you have a Moment of Um question that seems kind of fishy? Send it to us at BrainsOn.org/contact, and we’ll chew on the answer.

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