If you were a lot hairier and quite a bit smaller, you wouldn’t need a scuba tank to breathe underwater.

It’s a trick used by hundreds of insect species, including the Pygmy Backswimmer water bug. As they dive underwater, either hunting or avoiding being hunted, the dense hairs around their waxy bodies trap a bubble of air. They then use it as their own personal air pocket. Some of them can dive as deep as 30 meters underwater while breathing from the bubble.
Humans are lousy at breathing underwater. We just can’t get enough oxygen. Other mammals handle it much better. Whales, seals, even beavers leave us in the dust when it comes to holding a breath underwater.

Elephant seals can go underwater up two hours. The world record for humans is held by Branko Petrovic and is over 11 minutes. (But most of us would pass out after a minute or two.)

How do aquatic mammals breathe underwater?

The secret for other mammals is in the blood. Mammals that are natural divers have more myoglobin in their muscles. It’s an oxygen-binding protein. Some of our diving mammalian cousins have up to ten times more of it than we do. This lets them pack a lot more oxygen into their bodies for the long dives.

Bubble bugs and butt snorkels

Getting back to the bugs. The hairy air bubble isn’t the only way insects breathe underwater. A lot of them, such as the Lethocerus medius, or giant water bug, have snorkels. Sort of. Just imagine that you had a snorkel, but it was actually part of your body and connected to your butt. Then you’d be able to snorkel around like Lethocerus medius.

Giant water bug. Photo by Josh More.

What to do if the butt snorkel isn’t for you?

Maybe you’re thinking of trying the hairy waxy air pocket trick. Don’t hold your breath on it working out. Compared to a championship diving bug, you’re just too big, too warm-blooded and your metabolism is too high. You’d need a bubble of about one hundred square meters to keep you going underwater. And no matter how hairy or waxy you get, physics just won’t let you build a bubble that big.

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