ACCORDING to legend, hippos sweat blood. But the truth is more prosaic. They actually secrete a slime containing pigments that protect them against bacterial infections and the sun’s rays.
Hippos lack sweat glands, but they use specialised subdermal glands to secrete a slimy substance that turns from red to brown as the pigment molecules polymerise. The slime helps keep the animals cool, and scientists suspected it had antibacterial and sunscreen properties too.
That has now been confirmed by a team led by Yoko Saikawa at Keio University in Yokohama, Japan. The researchers collected fresh slime by mopping a hippo’s skin…
