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!