The Indestructible Water Bear: Tardigrades Explained

If an animal can survive the vacuum of space, extreme radiation, and boiling temperatures that would kill any other creature, then it earns the title of the toughest animal on Earth.

If the average size of a tardigrade is between 0.3 to 0.5 millimeters, and if 1 millimeter is much larger than that range, then they are microscopic animals.

If true extremophiles "love" and require extreme conditions to grow, and if tardigrades only enter survival mode to "tolerate" those conditions while preferring wet moss, then they are extremotolerant.

If tardigrades can survive the harshness of the vacuum and radiation of space, then scientists study them to understand the possibility of "panspermia" or life traveling between worlds.

If tardigrades require a thin layer of water around their bodies to stay active and feed, and if damp moss holds moisture effectively, then moss is the ideal habitat to find them.

If a tardigrade loses almost all its body water, and if it retracts its head and legs into a dried-out ball to protect itself, then this dormant state is known as a tun.

If the TARDIS experiment exposed dried tardigrades to the open vacuum and UV radiation of space, and if they were successfully revived upon returning to Earth, then they survived the exposure.

If an extremophile is defined by the ability to endure conditions that are fatal to most life, and if tardigrades survive heat, cold, no oxygen, vacuum, and dehydration, then they fit all these criteria.

If tardigrades have specialized mouthparts called stylets to pierce surfaces, then they use them to suck the juices out of algae, moss cells, or tiny rotifers.

If a tun can still be physically crushed or eaten by a predator, then it is not "immune to all death," even though it is very difficult to kill with climate extremes.

If metabolism is the set of chemical reactions that keep an animal alive, and if the tun state is defined by "stopping" life to protect it, then the metabolism must drop to nearly zero.

If the animal has a segmented body with eight legs and moves in a way that resembles a microscopic bear in water, then "water bear" is the logical nickname.

If a tardigrade enters a state where all signs of life like breathing and digestion stop until water returns, then that physiological process is called cryptobiosis.

If tardigrades use cryptobiosis to protect their cells, then they can withstand extreme cold, space vacuums, high radiation, and massive pressure; however, they cannot survive being vaporized by lava.

If a tardigrade is classified as a polyextremophile with four segments on its body, and if each segment has a pair of legs, then the total number of legs is eight.

If scientists discovered a "damage suppressor" protein that shields tardigrade cells from X-ray damage, and if its scientific abbreviation is Dsup, then that is the correct term.

If cryptobiosis is a response to environmental stress, then the loss of water, freezing cold, lack of oxygen, or high salinity will all trigger the transition into a tun state.

If the tun state is caused by dehydration, and if the animal's life processes restart once it is rehydrated, then the missing ingredient required for revival is water.

If a tardigrade is a microscopic invertebrate, then it has a cuticle for protection, claws for grip, stylets for feeding, and a segmented body, but it lacks any form of wings.

If the record for survival in a dried state is closer to 30 years according to scientific studies, then a 100-year claim is currently considered a myth or unproven exaggeration.