The hardest thing to kill?

Hello internet. Today I will be talking about the hardest animal to kill...the tardigrade.

The tardigrade is a really small animal, only growing to about 1 millimeter when they're fully grown.
They're short and plump with 4 pairs of legs and 4-8 "claws". They usually grow and live in moss or lichen and, if collected, can be viewed even with a low-power common microscope. Heck, you can even see it with your naked eye (if you have really good vision).

A tardigrade under a microscope.

This animal is known as a extremophile [comes from the Latin term extremus (extreme) and the Greek term philia (love)]. Extremophiles are basically organisms that can thrive in very harsh conditions that would usually kill most life on Earth.

The following categories are the things the tardigrade can withstand:

• Temperature

The tardigrade can withstand being heated to 151°C (304°F) and being chilled to -273ºC (-458ºF), which is about one kelvin away from absolute zero!

• Pressure

Tardigrades can withstand very high pressure, some even surviving 1,200 times atmospheric pressure. They can also survive very low pressure too, even surviving outer space. In fact, they were sent to and exposed to the vacuum of space, and also harmful (to humans) UV rays on a mission codenamed "TARDIS". 

• Dehydration

Some tardigrades can withstand being without water for up to ten years. In fact, they can do something that very little other species can do. They can go into a state called cryptobiosis.  Cryptobiosis is basically hibernation, but a bit more advanced. In this state, their metabolism lowers to less than 0.01% of normal and their water composition lowers to about 1% of normal. In this state, tardigrades are also known as a tun.

• Radiation

One species of tardigrade, called the milnesium tardigradum can withstand over about 5000 Gy while a dose of 4-10 Gy can kill a human. Their ability to lower their water composition provides fewer reactants for the radiation to react to. Ha! Suck it, cockroach!

• Environmental toxins

The tardigrade can also survive toxins via chemobiosis, which is, as you probably guessed, another way of entering the state of cryptobiosis.

• Outer space

I know I'm covering this topic again, but this subject is really cool, and I have something else to mention. Remember when I said several specimens were exposed to the vacuum of space? Well, some even reproduced and gave birth to more tardigrades! When they came back, they were like "Hey! You look familiar! Anyways, say hello to my kids! They're healthy as ever, but it was a little cold up there, however I didn't know we could fly!" Just kidding, I made that up, but the giving birth to new tardigrades and being healthy part, that was real.

So yeah. Anyways, sorry about the late post. I was on a tight and homework-filled schedule.

Interesting fact of the day: Hong Kong is the only place name that you can say without moving any part of your mouth (including teeth, tongue, lips, etc.). Also, I bet a lot of people will try it after reading that (seriously, it works).