Tardigrade Trivia Questions

Tardigrades are multicellular animals (eukaryotes) in the phylum Tardigrada, closely related to arthropods. They have complex organs, unlike bacteria.

The average tardigrade is about 0.5 mm long. The largest species reaches just 1.5 mm, still barely visible without magnification.

Tardigrades have eight legs but belong to the phylum Tardigrada, not Insecta. Insects have six legs and three body segments.

Tardigrades are nicknamed water bears because of their bear-like appearance and movement when viewed under a microscope.

When dehydrated, tardigrades curl into a tun and reduce metabolic activity to less than 0.01% of normal, allowing them to survive extreme conditions.

When dehydrated, tardigrades contract into a tun shape, slowing metabolism to nearly zero. This allows them to survive years without water.

In 2007, tardigrades were exposed to the vacuum and radiation of space on a European Space Agency mission and survived, though some died from UV radiation.

Other animals like some frogs, turtles, and nematodes can also survive being frozen for long periods. Tardigrades are not unique in this ability.

While hardy, tardigrades cannot survive boiling water. Their upper thermal limit is around 300°F (150°C) only in a dehydrated state, and not for long.

Experiments have shown that tardigrades can survive exposure to the vacuum and radiation of space for short periods by entering a cryptobiotic state.

The longest recorded revival of a tardigrade from dormancy is about 120 years, not 1,000 years. Claims of longer lifespans are unverified.

Tardigrades have no respiratory or circulatory systems. They absorb oxygen directly through their outer cuticle and distribute it via body fluids.

Goeze named them 'Kleiner Wasserbär' (little water bear) in 1773. The name Tardigrada was later given by Lazzaro Spallanzani in 1777.

Other organisms, such as certain bacteria, lichens, and even some insect eggs, have also survived space vacuum experiments. Tardigrades are not unique in this ability.

No tardigrades have been confirmed on the Moon. Some were on a crashed Israeli lander in 2019, but their survival is highly unlikely and unverified.

Despite their microscopic size, tardigrades have a full digestive tract with a mouth, pharynx, intestine, and anus, allowing them to eat and excrete waste.