What are extremophiles, you say? They are organisms that can survive extreme environmental conditions, and are some of the most amazing creatures on this planet. One particular animal extremophile is particularly unique and is a master of survival.

First thing you should know, these bears aren’t really too huggable (unless you’re <1mm tall, which hopefully you’re not or I’ll send my amoebae out to slowly eat you. Water bears aren’t cute and cuddly… they’re rough, tough, and make you look like someone who cries over spilt milk. There are many animals that are extremely resistant to the Earth’s climate, but water bears (Tardigrades) have taken this to an extreme, and can even survive in space for some time, also. Water bears belong to the minor phylum Tardigrada, which has not been studied too carefully and there are about 1,000 discovered species, although the actual species count has been thought to be much more than that, for biologists haven’t delved into their Phylum much. Tardigrades can survive the following in a state of crytobiosis, or total dehydration in a state of no metabolism, whatsoever:

· Exposure to a vacuum and all of the sun’s energy, not just heat, light, and UV rays as we experience it from under Earth’s atmosphere, but also massive amounts of gamma rays and X-rays, too.

· Exposure to 570,000 rads of X-ray radiation, about 500 times the amount of rads it takes to kill a human.

· Survival of cryptobiosis (dry state) for a decade.

· Survival of all of the conditions of space for 10 days! You would die in a matter of seconds! (or less than one)

· Exposure to as high of a pressure as 6,000 Earthen atmospheres, or a pressure as low as a vacuum (already explained).

· Possibly able to survive high concentrations of alcohol.

· Exposure to temperatures of up to 151 degrees Celsius for a few minutes or as low as -200 degrees Celsius for days or-272 degrees Celsius for a couple of minutes. Note that -273.15 degrees Celsius is absolute zero, in which atomic movement slows to a halt and the enigmatic Bose-Einstein condensate forms!

The key to a water bear’s extremophile status is the cryptobiotic stage; because without this, many abilities would be taken away, such as a high immunity to radiation. The Tardigrade is almost dead in the cryptobiotic stage, other than the fact that it can revive itself from this state. Because there is no water in the body of the Tardigrade while in a cryptobiotic state to aid metabolism, the Tardigrade cannot go through any physical changes (from self) while dehydrated.

Although I have said that the water bear does not undergo any form of metabolism during cryptobiosis, it actually has a metabolic rate of 0.1%, rendering it almost dead, but yet, not dead. As I said earlier, it can stay in this state for about a decade.

Water bears also have an interesting anatomy. They do note have a respiratory or circulatory system, as their minute size would render them useless, but water bears still do retain a small nervous system. They have four pairs of legs, which can have claws at the ends of them. Water bears actually got their informal name from their locomotion method, which is thought to resemble that of a bear. Water bears are sometimes also referred to informally as “moss piglets”, because of their common inhabitance of moss, but does that have anything to do with water bear anatomy? Getting back on topic, water bears are usually not hermaphroditic, meaning that there are usually males and females. Eggs can still be functional for quite a long time before dying. Some species of water bears actually have rudimentary excretory organs. Water bears, on average, have about 40,000 cells in their bodies. Food is consumed by piercing prey with the two sharp stylets within their oral cavity, then sucking food in with the power of their strong pharynx. A relatively large brain inhabits their body including 5 nerve ganglia throughout the body. A nerve ganglion basically acts as a brain for quicker reaction, or other uses. Also, not all species can form a “tun”, or the cryptobiotic state in which the legs are pulled in and metabolism is shut down, such as deep sea species which cannot achieve a tun (awkward pun made by accident). In every other organism, they are considered dead when metabolism stops, but Tardigrades, on the other hand, revive themselves miraculously by replacing the water in their membrane lipids (oily substances) with the sugar “trehalose”.

As with eating habits and inhabitation, first I must say water bears live just about everywhere in the world. Unlike most animal species which are more numerous towards temperate/tropical areas, water bear species are much more diverse toward polar regions. Water bears like to live in wet, damp areas such as moss or algae, which are favorites, but can live almost virtually anywhere without being harmed. They tend to eat moss and photosynthetic as well as various other single cell contents, but are rarely carnivorous, eating radiolarians, nematodes, and sometimes even other Tardigrades.

Did you know?

· Water bears have been revived after 120 years of cryptobiotic stasis in a botanical museum.

· Some water bear species only include females.

· Some people have even speculated that water bears came here from Mars.

· Water bears are actually close relatives of Nematodes, from DNA sequencing proof and pharyngeal similarities.

· Estimated to be able to live for 50+ years.

· For all of you annoyingly persistent annoyers out there… WATER BEARS ARE NOT RELATED TO BEARS BY ANY MEANS! (other than that all organisms are perhaps related with at least a common ancestor, but let us leave the topic of Abiogenesis for another date).

· DID YOU KNOW that if you use the words “Tardigrade” and “Panspermia” in the same sentence, I will instantly murder you?

· There are multiple sites/videos that tell you how to safely collect water bears, but please don’t hurt/abuse them. They can still get squashed even though they are seemingly invincible. If you really like water bears and are not too clumsy, this shouldn’t impose a problem.

Anyways… thank you VERY much for reading, look for more articles in the nigh future, and please click “I like it!”