YOUR WEEKLY DOSE OF WOWZERS AND WONDER FROM THE NATURAL WORLD
So far at Wowzerful, we’ve talked about things you can see, touch, or even visit.
With today’s topic, we’re switching things up a bit. You’ll need a microscope and some keen eyes to discover this elusive creature.
But don’t let the size of this week’s featured friend fool you—they’re seriously cool!
Let’s get tiny and talk about tardigrades!
Tardigrades—also known as “water bears” and “moss piglets” — have been around for more than 500 million years.
First discovered in 1773 by Johann August Ephraim Goeze, more than 1,000 tardigrade species are known today, with new ones found nearly every year.
Nearly impossible to see with the naked eye, these tiny, transparent, eight-legged creatures measure between 0.05 mm (0.002 in) and 1.2 mm (0.05 in) long.
Their telescoping mouth, referred to as a pharyngeal apparatus, can dart out and suck the nutrients from whatever they’re trying to eat.
These omnivores often dine on moss and algae, but they’ll also eat other bacteria and microorganisms. They’re even known to resort to cannibalism (eating other members of their species in order to survive).
Speaking of surviving, tardigrades can live just about anywhere, as long as there is a tiny bit of moisture.
Despite their size, they are shockingly tough! Freezing, dehydration and oxygen deprivation pose no threat to them.
And, thanks to a unique protein that protects their DNA, tardigrades can handle 100 times the radiation that a human can!
Much of their ability to survive is due to a special trick they have up their sleeves — they can enter something called a tun state.
In this state, they turn themselves into a little ball, almost like a pill bug or potato bug, and suspend their metabolism.
In other words, they put their lives on hold until more favourable conditions return. It’s kind of like stepping into a cryogenic sleeping chamber from the movies (ask your parents!).
While in their tun state, they don’t need to eat, breathe, or drink water. Amazingly, they can survive in this way for up to 30 years! Scientists call this incredible feat cryptobiosis.
While in this “switched off” mode, wind or flowing water can carry them away to new environments. When they settle in improved conditions, they’ll leave the tun state and start a new colony of tardigrades!
Though they’re super tough, they’re not invincible.
It turns out that tardigrades have one weakness — hot water.
At temperatures of 37.8ºC (100ºF), these little guys only last about a day before wilting away.
When not in their tun state, tardigrades typically have a lifespan of 3 to 30 months.
But don’t worry about the fact that these little extremophiles are everywhere. They’re mostly harmless.
In fact, there’s a good chance you accidentally swallow a few of them from time to time as you eat or drink. Rest assured, they’re no match for the human digestive system!
But when it comes to this species’ long-term survival, there’s a good chance tardigrades will be suckling on algae, moss, and bacteria long after we humans are gone!
While tardigrades are microscopic, they’re barely so. This means if you grab some sediment from a local pond and break out a basic microscope, there’s a good chance you can find some tardigrades yourself!
Unlike most other creatures, tardigrades are born with all of their adult cells. Instead of multiplying their cells to grow, tardigrade cells simply get bigger as they get older.
While tardigrades typically reproduce by laying eggs, there are some that are capable of cloning themselves. This means that just a single tardigrade tun can start a completely new colony!
Scientists are looking for ways to use the protein which protects a tardigrade’s DNA to make drought-resistant versions of yeast, helpful bacteria, crops, and even improve the temperature sensitivity of medications!
Get a close-up look at tardigrades and the various places they live in this quick video from The Dodo.