# Is there any species that uses no water? (If so, probably microscopic or insect.) **URL:** \ **Category:** Factual Questions\ **Created:** [October 11, 2018, 2:23pm UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802 "2018-10-11T14:23:07Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Steven\_Estes](https://avatars.discourse-cdn.com/v4/letter/s/94ad74/32.png) [@Steven\_Estes](https://boards.straightdope.com/u/Steven_Estes)\ **Post date:** [October 11, 2018, 2:23pm UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/1 "2018-10-11T14:23:07Z")
Is there any species that uses no water? (If so, probably microscopic or insect.) ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [October 11, 2018, 2:26pm UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/2 "2018-10-11T14:26:34Z")
Earth life chemistry is water based. So no, not any species we know. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [October 11, 2018, 3:07pm UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/3 "2018-10-11T15:07:24Z")
The answer to this may not be possible until we understand what the OP means by \*using \*water. [Purple sulfur bacteria](https://en.wikipedia.org/wiki/Purple_sulfur_bacteria) > [@](#): > > The purple sulfur bacteria (PSB) are part of a group of Proteobacteria capable of photosynthesis, collectively referred to as purple bacteria. They are anaerobic or microaerophilic, and are often found in stratified water environments including hot springs, stagnant water bodies, as well as microbial mats in intertidal zones.[4] Unlike plants, algae, and cyanobacteria, purple sulfur bacteria do not use water as their reducing agent, and therefore do not produce oxygen. Instead, they can use sulfur in the form of sulfide, or thiosulfate (as well, some species can use H2, Fe2+, or NO2−) as the electron donor in their photosynthetic pathways.[4] The sulfur is oxidized to produce granules of elemental sulfur. This, in turn, may be oxidized to form sulfuric acid. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [October 11, 2018, 3:30pm UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/4 "2018-10-11T15:30:24Z")
Given that protoplasm consists of molecules in an aqueous solution, all cellular life requires water. Dormant viruses don’t contain water, but require living cells to reproduce, so they also require water. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [October 11, 2018, 3:56pm UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/5 "2018-10-11T15:56:38Z")
We need more clarification on “uses no water”. Bacteria can survive a ride to the moon and back : exposed to space and the worst dry conditions. They can survive encapsulated in amber for 30 million years… [https://www.panspermia.org/bacteria.htm](https://www.panspermia.org/bacteria.htm) ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [October 11, 2018, 8:32pm UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/6 "2018-10-11T20:32:57Z")
> [@Exapno\_Mapcase](#): > > The answer to this may not be possible until we understand what the OP means by \*using \*water. > > [Purple sulfur bacteria](https://en.wikipedia.org/wiki/Purple_sulfur_bacteria) That’s fascinating. But also only part of their metabolism. Could their body chemistry function without any water produced or consumed by reactions? ---
**Author:** ![vperry1](https://avatars.discourse-cdn.com/v4/letter/v/ee7513/32.png) [@vperry1](https://boards.straightdope.com/u/vperry1)\ **Post date:** [October 11, 2018, 11:17pm UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/7 "2018-10-11T23:17:23Z")
I don’t know if they count, but Tartigrades, or water bears, seem to come close to what you mean. Cite from Wikipedia: _Tardigrades are considered to be able to survive even complete global mass extinction events due to astrophysical events, such as gamma-ray bursts, or large meteorite impacts. Some of them can withstand extremely cold temperatures down to 1 K (−458 °F; −272 °C) (close to absolute zero), while others can withstand extremely hot temperatures up to 420 K (300 °F; 150 °C)[36] for several minutes, pressures about six times greater than those found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space. **They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce.** Tardigrades that live in harsh conditions undergo an annual process of cyclomorphosis, allowing for survival in sub-zero temperatures._ Photo: ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 12, 2018, 12:19am UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/8 "2018-10-12T00:19:20Z")
There are plenty of animals that don’t ever drink, and get their water indirectly. It’s a bit of a grey area - if chicken soup doesn’t count as water, presumably humans could too in principle! But I suspect that’s not what OP meant. As others have pointed out, all life is based on reactions that can take place only in aqueous solution. ---
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [October 12, 2018, 12:54am UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/9 "2018-10-12T00:54:29Z")
The bacteria and water bears mentioned in this thread don’t fit the OP’s criteria. They still need and use water. They can survive a very long time without it, but still need it in order to reproduce or spore or grow or whatever. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [October 12, 2018, 1:30am UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/10 "2018-10-12T01:30:26Z")
> [@vperry1](#): > > I don’t know if they count, but Tartigrades, or water bears, seem to come close to what you mean. > … > Photo: The URL in **vperry1** ’s link can be copied (with "-marks deleted) into the Chrome address bar and an image appears. It can be copied into the ‘src’ of an html ‘img’ tag and the image appears. But I don’t know how to click here at SDMB and get the image to appear directly. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 12, 2018, 1:41am UTC](https://boards.straightdope.com/t/is-there-any-species-that-uses-no-water-if-so-probably-microscopic-or-insect/822802/11 "2018-10-12T01:41:05Z")
> [@septimus](#): > > The URL in **vperry1** ’s link can be copied (with "-marks deleted) into the Chrome address bar and an image appears. It can be copied into the ‘src’ of an html ‘img’ tag and the image appears. But I don’t know how to click here at SDMB and get the image to appear directly. I immersed the tardigrade URL in an isotonic solution and it worked fine.