How Fish Breathe Underwater?

Text us a question or any feedback Ever watched a fish constantly opening and closing its mouth and wondered what it's doing? In this episode of I Wonder, we discover how fish breathe underwater, why gills are so amazing, and why a fish can't simply breathe air like we do. Written by Zach Margiotta What's Your Wonder? Is there something you’ve been wondering about that you think would make a great episode of I Wonder? We’d love to hear from you! Submit your question through our website, and ...