How do animals breathe underwater?

Our lungs are great at getting oxygen out of the air, but if we needed to do that underwater, we'd be sunk. So how do fish, shrimp, jellyfish and other marine animals breathe underwater? And what happens when there is no oxygen in the water for them to breathe? We answer those questions plus a brand new Moment of Um tackles this sticky one: "Why do we have earwax?" And a new group of listeners gets inducted into the Brains Honor Roll! Give a listen!Today Brains On is sponsored by:• Acer Swift 5 (acer.com -- enter BRAINSON at checkout for 10% discount)• Mr. Clean Magic Eraser (mrclean.com/brainson)Music in this episode by Good Old Neon.