[ ♪ INTRO ] Thanks to Brilliant for supporting this SciShow video.

You can keep building your STEM skills at Brilliant.org/SciShow with 20% off an annual premium subscription! When you go to the toy store, you might see a box on the shelf that advertises living animals.

And while it’s not quite the same as a dog from the shelter, you could buy that box and be the proud owner of a troupe of brine shrimp. Real live brine shrimp. If you want to see one in action, check out the video on the Journey to the Microcosmos channel, brought to you by some of the same people who make SciShow.

Regardless, these incredibly adapted sea creatures could have been sitting on the shelf for years without food or oxygen until you came along and revived them from their dormant slumber. And theoretically, human embryos could do the same thing. The brine shrimp Artemia can have a pretty straight forward life cycle. .

A pregnant Artemia in water with the right salt concentration, pH, and other qualities will give birth to live babies who become successful adults. But in more extreme water, like the harsh salt lakes these critters might have appeared in 400 million years ago, a pregnant Artemia can release dormant eggs. Those embryos are in biological arrest.

They basically pause their essential functions, like turning food into energy and using their body’s nutrients, so that they can become dehydrated eggs called cysts. In fact, researchers have calculated that cyst metabolism goes down to at least 50,000 times lower than their siblings that don’t go dormant. The cyst also has protective layers that keep potentially harmful liquids out.

And this, plus the metabolic changes, lets Artemia survive conditions that could otherwise kill them. So these dormant animals are protected from their environment until it becomes easier to live in. And they can stay this way for years!

One study from the University of California, Davis found that at least 60% of cysts can hatch after four years of being in extreme temperatures and without oxygen. And that number could be higher. The longer these brine shrimp pause their metabolism as cysts, the longer it takes them to hatch once they have oxygen and all that good stuff they need to thrive.

That could be because they need to repair additional damage after spending so much time in low-oxygen conditions. Or it might just take longer to speed their metabolism back up. Either way, the researchers in this study eventually moved on with their lives after four years of waiting for dormant Artemia to molt.

So it’s possible that even more of the cysts might have hatched if given more time. And what’s possibly even cooler is that even after all that time in cyst mode, most of the Artemia appeared to be totally fine! The four-year study found that only 4% of them showed developmental deficiencies like stunted appendages.

That’s partly because of the cyst’s protective layers. But also, certain alcohols, sugars, and proteins in the embryo likely protect the animal’s other proteins from breaking down. So the brine shrimp you buy at the store could be dormant for years and still swim around like nothing happened once you put them in a nice, hospitable fish bowl.

And hypothetically, human embryos can do this, too!. Pretty much every other kind of animal can undergo this kind of embryonic dormancy. It’s just that Artemia are born in a way that allows them to hatch without anyone else’s help after dormancy.

Other animals like mice and humans need the embryo to be implanted, and birds need eggs to be incubated before they emerge. So while we can make this kind of dormancy happen in larger animals in the lab, brine shrimp are pretty impressive for doing it all on their own. And they look cool doing it!

Dehydrated cysts curve inward in different ways from non-dormant eggs. So admiring them is one way to learn about geometry, but you can do that in other ways that don’t involve sharing your home with shrimp, like using Brilliant. Brilliant is an online learning platform with guided courses in math and science, including their course called “Beautiful Geometry.” It’s an interactive course that provides real world examples like fractals and origami folding, to show you how beautiful geometry is all around you in your everyday life.

This course even has an art gallery section, complete with a puzzle! And if you’re traveling to pick up some brine shrimp for yourself, you can still complete Brilliant courses as you go, because they are now available offline using their iOS and Android app. To get started for free, click the link in the description down below or visit Brilliant.org/SciShow.

You’ll get 20% off the annual Premium subscription. Thanks to Brilliant for supporting this video and thank you for watching! [ ♪ OUTRO ]