se7enW
Back to What
📖 what

What Is a Tardigrade?

BiologyZoology

Quick Answer

Tardigrades ("water bears") are microscopic eight-legged animals, typically 0.1-1.5 mm long, famous for being the most resilient animals known — they can survive extreme temperatures, radiation, vacuum of space, and pressures that would destroy most life.

The Full Story

Tardigrades are micro-animals found in nearly every habitat on Earth, from deep ocean trenches to mountain peaks, from tropical rainforests to Antarctic ice. About 1,300 species are known. Their extraordinary survival abilities come from a state called cryptobiosis: when conditions become hostile, tardigrades expel nearly all water from their bodies, retract their legs, and form a desiccated "tun" that can survive almost anything. They have been revived after 30 years of frozen storage, survived temperatures from -272 degrees Celsius (near absolute zero) to 150 degrees Celsius, endured pressures of 6,000 atmospheres (6 times greater than the deepest ocean), withstood radiation doses 1,000 times the lethal human dose, and even survived 10 days of direct exposure to the vacuum and radiation of outer space (on the TARDIS experiment aboard the ISS). A unique protein called Dsup (damage suppressor) protects their DNA from radiation damage.

Key Facts

1.Tardigrades can survive temperatures from -272 degrees Celsius to 150 degrees Celsius, pressures of 6,000 atmospheres, and radiation of 5,000 Gy (the lethal dose for humans is about 5 Gy).
2.In 2007, tardigrades became the first animals known to survive direct exposure to outer space — they were revived after 10 days on the exterior of a spacecraft.
3.About 1,300 tardigrade species have been described, and they are found on every continent including Antarctica.

YouTube Angle

Suggested video title for this topic:

"Tardigrades — The Toughest Animals in the Universe"