Give Now  »

Noon Edition

No Sweat for Hippos

In the pantheon of wild animals, hippos occupy a relatively humble position. They're not quite as fierce and exciting as rhinos, not as large and loveable as elephants, and not nearly as awe inspiring as the big cats. The truth is that we tend to take the hippo for granted. It waddles around, covers itself with mud, and eats plants. Bor-ing.

However, hippos are a lot cooler than we normally allow. In fact, hippos never sweat. Not because they're so calm and collected, although that might be true. Quite literally, hippos do not produce sweat. The reddish-orange stuff that does emerge from large pores deep in their skin might look like sweat, but according to a study by two Japanese scientists, hippo goop is a combination of anti-biotic and sunscreen.

After analyzing the stuff in the lab, the scientists found that the pigments that give hippo goop its reddish color are highly acidic and help keep certain kinds of harmful bacteria from growing. That probably explains why hippos can sustain gashes and injuries during fights with other hippos and not suffer from infection.

The scientists also found that the goop absorbs the sun's ultraviolet rays, which can cause sunburn and skin cancer. So hippos enjoy a kind of natural sunscreen.

So what? Is this just an interesting fact, or might hippo goop result in some practical application for humans? So far the goop remains strictly a hippo thing, so hippo skin secretions may not yet benefit humankind, but it's still pretty cool.

Support For Indiana Public Media Comes From

About A Moment of Science