Tardigrades Survival Skills

Topic: Microbiology

Uploaded By Fhadeea A.

Tardigrades are also known as water bears or moss piglets. They are a chubby, microscopic eight-legged invertebrate animal and are related to arthropods and nematodes. An Italian biologist named Lazzaro Spallanzani gave the name to these creatures “Tardigrada”, meaning "slow steppers".

Tardigrades live in a variety of environments but are most common to be found in body of freshwater and moist environments, many species being found in environments such as lakes, ponds, and meadows, but can also be found in roofs and stone walls. Tardigrades eat mostly algae and flowering plants, but can also eat other tardigrades.

Tardigrades are known for their good survival skills, and are categorised as “extremophile” animals.

  • They’re the first known animal to have survived exposure of outer space without any protection, In 2007, dehydrated tardigrades were taken into low Earth orbit. For 10 days they were exposed to vacuum and radiation of space, and during their time back on earth, several of them have survived, but many died shortly after.
  • Has been known to survive extreme temperatures (including if you boil them) and radiation that are lethal to humans.
  • Have been known to survive toxic substances.

How did they do this? One of the practices that Tardigrades do is to be in a form called cryptobiosis.When they face extreme conditions the cryptobiosis process causes the Tardigrade to go in a state which metabolic activity is slowed.

There are various kinds of cryptobiosis, specifically:
  • Anhydrobiosis: Anhydrobiosis is the most studied form of cryptobiosis, anhydrobiosis is a response to lack of water. Tardigrades enters this state by turning into a “tun”, dehydrating itself by losing its store water. During the state they create different proteins and sugars that help protect its cells. Once these cell protectants are synthesized, they reduce, and suspends its metabolism. When extreme conditions improve, the Tardigrade, helped by the hydration from water intake, activates its metabolism.
  • Anoxybiosis: Occurs during lack of oxygen. The process starts when they enter a state of inactivity leaving their body fully stretched and take in water.
  • Cryobiosis: Cryobisis is a form that protects the Tardigrade from low temperatures, cryobiosis initiates using proteins to freeze water cells that are small to avoid breakage.
  • Osmobiosis: The least studied, forms during increase of the environment’s salt concentration.

Some may question, can Tardigrades die? Yes, they can, and there are various ways tardigrades can be killed easily too. Tardigrades can die from:
  • Water temperatures of about 100 degrees Fahrenheit can kill tardigrades in 24 hours
  • If they aren’t in their cryptobiosis state, they can easily die.
  • They have natural predators, including nematodes, other tardigrades, and bacteria.
  • The average lifespan of tardigrades commonly lives for 3-4 months, although some species can take years to survive during their tun state.
Thanks for reading!