When you and I take a deep breath, we pull air into our lungs. That’s because humans are mammals. But fish aren’t mammals. They usually don’t breathe air. They usually don’t have lungs. That’s what I ...
How do fish breathe underwater? -- Mordechai Linfield, 8, Silver Spring With all the talk this summer about those exotic snakeheads climbing out of ponds and trotting about in the open air, we almost ...