#moss piglets

Ok I know you probably wanted some basic information on them (microscopic bear like things that can survive mostly anything including the dinosaur extinction and space) but I’m going to use this opportunity to do a biology rant, I apologize for your timing with this.

I just saw an article explaining how to best capitalize tardigrades by selling them as pets. First of all, these are microscopic beings, why would you possibly want them as a pet when you have to look through a microscope to even see them. Second of all, since when has it been ok to take wild animals directly from the wild, and sell them?? It’s one thing if it’s with strays or animals who would do better with someone caring for them, but with tardigrades they don’t need any help. These things were built to survive, I mean deepest parts of the ocean kind of survive, they survived the dinosaur extinction for fucks sake, which sure it wasn’t the largest extinction event on this planet (The Great Oxidation killed 99% of life on the planet, all of which was bacteria though) but it still took out, what? 70% of life? Tardigrades have been around for a long time and are very resilient, so why are we trying to domesticate them?? Is it just so people can make a profit all of them???

Which leads me to bioethics. While I’m using the term in its broadest definition, ethics concerning biological lifeforms, it generally does have a more specific usage. So in terms of bioethics I say it’s ok as long as it doesn’t directly or indirectly harm the animal(s). For example the glow in the dark rabbit genetic experiment. It (to my knowledge) did not directly harm the rabbit, they simply edited the dna in its skin cells to have bioluminescence, and being that it wasn’t going to be released back into the wild (it was a domesticated rabbit) the glow in the dark trait would not put it at risk in the wild. Another part of it is that the experiment was actually useful, they could take the shedded glow in the dark skin cells from the rabbit (and it’s children which it passed the trait onto) to keep track of the location of cancer cells in humans, making it easier for them to stop cancer before it begins.

On the flip side, the selective breeding of Belgian Blue Horns is something that I am against. They narrowed down their genetic traits until they got so much muscle that in some cases it’s difficult for them to even walk on their own, they certainly can’t breed on their own, they need human assistance with that. The only reason people have continued with this selective breeding over a period of 150 years is that the cows provide more meat, and thus gets the sellers more profit (not even going into how that can effect the cow overpopulation also caused by humans). Then there was the Firefly Axolotl experiment, which I won’t go overly into due to the fact that I am digressing, but in vague summary, the animals were harmed but with the purpose of an outcome that would help people without a motive of money.

So I got a bit off topic but you get my point hopefully, using animals for human gain (money specifically) and also harming them in the process you’d think would be a pretty big no ethics wise. But here we are, with ethics laws not applying whatsoever to microscopic animals. They got shot out of a gun to see what velocities they could survive (the direct quotes of “Tardigrade jam” and “shattering on impact” were used to describe the outcomes), and then they were also shot into space to see how long they could last up there without any life support (10 minutes). We wouldn’t be able to do this with any other animals, so why is it ok with tardigrades? And now we’re taking them from their natural habitats to sell as pets? Why?? So you can invite your friend over and be like ok look at the petri dish through the microscope to see the microscopic being that vibes there instead of the environment it was meant to vibe in???? And the fact that people are openly discussing it like there’s no issue with it as well, I mean there seemed to be general sentiment of not taking other wild animals from their habitats to keep as a pet or sell for a profit, so why does it not apply to tardigrades and other microscopic creatures?

I know a lot of people don’t actually know what tardigrades are, and are not well versed in biology or bioethics, but I still think that it’s something that should at least has room to be discussed. It’s obviously not a priority discussion either, with all of the other very important topics to be discussed/heard.

Water Bear (Tardigrades)

A number of science blogs/instagrams/facebook pages/etc have jumped on the tardigrade craze in recent years, to the point where water bears have even become something of a household name. As the world’s biggest number 1 fan of invertebrates (data not yet published), I find this is pretty exciting. I always love it when obscure and fascinating inverts get the attention of the public. But the amount of misinformation being spread has gotten out of control. And boy howdy do I hate to be that guy, but... 

-TARDIGRADES DIE REALLY EASILY

No, really. They do. Throw a living, active tardigrade into a jacuzzi and it will die. Teleport it to the Sahara desert and it will die. Launch it into the moon and it will very much die. 

Here’s the thing: living and growing tardigrades are delicate and squishy creatures. They die all the time, be it from drying out, disease, predation, temperature extremes, or even just being squished between microscope slides (see above picture. Sorry little guy). In order to survive extreme conditions, they need to enter a state of anhydrobiosis, This is the process where their bodies slowly desiccate and enter a state of suspended animation. Only once they have entered this state can they survive all sort of extremes.

The internet will have you believe that tardigrades can not just live but thrive, grow, and reproduce in the vacuum of space or in boiling water or what have you. But they can’t. They have to be in an anhydrobiotic state. And even then, many of them will fail to resuscitate once exposed to these extreme conditions. Not to mention...

-TARDIGRADES KINDA SUCK AT ANHYDROBIOSIS

Water bears can’t just turn indestructible at a moment’s notice. Only under specific conditions can they turn into tuns (which is the term for a water bear in its desiccated state). One study showed that the tardigrade species Macrobiotus areolatus requires a relative humidity of 70-95% in order to successfully become a tun. Any drier, and they just flat out die. Not only that, but it took them 4 whole days for them to reduce their bodily water content to the amount needed for the tuns to survive extreme conditions. But once they enter this state they can survive up to a century and then  oh wait nevermind they only last like a decade.

-THEY ONLY LAST LIKE A DECADE

The oft-repeated factoid that they can stay dried out for over a century only to spring back to life after being sprinkled with water comes from an exaggeration of a single case from a study in the 1940′s. What happened was that a 120 year-old sample of moss was rehydrated and inspected under the scope. Some of the tuns in the sample extended a bit in size, but otherwise remained in their state (presumably long dead). However, a single tun did re-hydrate and some movement of the limbs was noted for a short moment. It was observed over the next few days and no more movement was noted, with it eventually decomposing. The likely explanation is that water re-entering the organism caused it to inflate like a water balloon, and thus appear to show some movement. 

From current scientific literature, the record-holders are certain species of moss piglets that can last up to 7-8 years in suspended animation an antarctic tardigrade that resurrected after 30 years, which was still beat by a nematode resurrected after 39 years. On the other hand, several species can only last up to a few months before no longer being viable.

And last but not least...

-THEY AREN’T THE ONLY ONES WHO CAN SURVIVE EXTREME CONDITIONS WHILE IN A STATE OF SUSPENDED ANIMATION

Thousands of other species of invertebrates, fungi, and protozoans can do it too, sometimes better than tardigrades can. This isn’t to say that tardigrades aren’t fascinating or unique, but that other, less-conventionally-cute organisms sometimes get ignored as people often imply that extreme survival is somehow unique to tardigrades. 

But let’s end this on a more tardigrade-positive note. Even active water bears are amazingly good at handling radiation, and in some cases can withstand higher doses while active than while in anhydrobiosis. A number of species can also withstand large swings in salinity and temperatures as low as -20 C and still thrive. 

Sources below!