EPT![[image loading]](http://www.fishpondinfo.com/hydra1.jpg)
Seeing how people want to know how to raise a hydra in the thread "Hydras, the origin of eyes", I decided to make a thread on how to raise your own hydras since I've petted them for some time.
**-Content-**
-Intro-
>What is Hydra?
>Why do I want a pet Hydra?
>Pros and Cons of having a pet Hydra?
-How to Secure a Hydra?-
>From nature
>Buying a Hydra
-How to Take Care of a Hydra?-
>Conditions which Hydras love
>How to feed your hydra
=Intro=
-What is a Hydra?
According to wikipedia,
Hydra is a genus of simple, fresh-water animals possessing radial symmetry. Hydras are predatory animals belonging to the phylum Cnidaria and the class Hydrozoa.
Let us translate it to some more humanly readable language.
Hydras are a kind of little critter that inhibit ponds and streams, lakes, and many other mild water environment. A good way to think about hydra is you take a Jellyfish, shrink it until it is about the size of a grain of rice, and tape it head-first onto a surface.
Let us see a magnified visual of a hydra so we get a feeling for it:
So, being a jellyfish taped to the surface, it behaves very similarly to a jellyfish, except it cannot swim around. Like a jellyfish, Hydra has sting cells that sting its prey and inject neurotoxins to paralyze it. Hydra will then engulf its prey by rolling its tentacles inward. Having only mouth and no anus, hydra will regurgitate the indigestible food out from its mouth.
As you might've learned in bio class, Hydras reproduce asexually by budding, It sprouts a fresh miniature hydra from the mother's body, and the miniature hydra detach itself.
+ Show Spoiler +
Here's a goofy code to transform a jellyfish into a hydra in scheme xD
![[image loading]](http://z.about.com/d/healing/1/0/Y/O/gtotem_jellyfish.jpg)
Jellyfish
(Define (Function-Jelly-To-Hydra Jellyfish)
(Tape-to-Surface (Flip-Up-Side-Down (Shrink Jellyfish))))
(Define Hydra (Function-Jelly-To-Hydra Jellyfish))
![[image loading]](http://www.fcps.k12.va.us/islandcreekes/ecology/Miscellaneous/Green%20Hydra/chlorella_in_hydra2.jpg)
Hydra
-Why do I want a Pet Hydra?
For very obvious reason. It's a HYDRA! It also requires minimum efforts to raise, and it is very sturdy. Hydras a beautiful creatures that are radially symmetric, something special to gaze at in a world where we associate animals with planar symmetry.
-Pros and Cons
Pro: Easy to raise, Nice to look at, Reproduce readily, makes you ponder about neurons and geometry and science.
Con: Might be hard to get, you don't get much emotional attachment
=How to Secure a Hydra?=
-From Nature
Hydras are ubiquitous creatures in many mild watery environments. People tend to overlook them because they are so tiny. What we need to do is to acquire a chunk of hydra's habitat instead of trying to pick hydras one by one.
Where do we start?
You might want to recall some local rivers or little creeks that flow around your neighborhood. I am sure there are many sources of natural water around where you live, even if you tend to ignore them on a daily basis.
Somewhere like this will be a good place to start.
![[image loading]](http://www1.istockphoto.com/file_thumbview_approve/2026346/2/istockphoto_2026346_very_small_bridge.jpg)
Start heading out with some clean water bottles, soda bottles are okay too, just rinse them a lot in the creek. Take the bottles to the creek, pond, lake, river, whatever is nearest to you.
Go down to the bank, and walk along it. You want to look for a dense patch of algae, water weed/moss of some sort. I would always go for "filamentous green algae". As its name implies, these kind of algue are made of little filaments, and resemble messy hair balls when in stagnant water, and flows like a lady's hair in moving water.
The look Something like this:
![[image loading]](http://www.lindenhurstil.org/lakescom/Images/main_pics/xAlgae04.JPG)
From the bank
![[image loading]](http://www.fbas.co.uk/blanketweed.jpeg)
When you pick it up
You should fill your water bottle with creek water, take a handful of these green algae (might be slightly disgusting but really you'll get over it), and stuff your bottles with a reasonable amount of them.
If you have multiple bottles, feel free to sample other niches of the water body, take a scoop from the top algae layer, fill that in one bottle, take a scoop from the muddy bottom, fill that in another bottle.
After you feel comfortible with your collection, start head home. It is important not to let the bottle get too hot, the heat will kill any interesting organisms inside. So put the bottles inside a backpack and head back asaply.
Once you are home you can transport your algae mess inside jars if you want, open the cap and let the water rest. By night time, take the jar/bottle and examine it closely under a lamp.
![[image loading]](http://www2.una.edu/microaquarium/images/General/Pond_Jar_4710cm.jpg)
Hydras are few millimeters long, so about the size of this bolded I in normal conditions, it can stretch to 3,4 times it's body length when trying to net preys, and it can shrink and curl into a tiny dot when threatened. They are transparent, sometimes a little bit yellow or green. So look for them. By good luck you may have some already moved themselves from the weed to the outer surface of your container.
If you do not find any hydras in your collection, wait a couple more days, maybe then they'll start to show up. My first jar of hydras were purely by accident, as I had not known they were lurking in it.
If still no luck, I am sure a jar of pond water contains many many other interesting organisms, little critters of all sorts of planktons and little wormies. So you can have some fun with those.
-Buying a Hydra
If you are lazy or do not have any natural water resources nearby, you can try to purchase some hydras. Hydras will probably free if you happen to find them as they are considered a pest inside aquariums. Because like mini-jellyfish, they eat freshly hatched fish.
I've tried and failed to find any online store that actually sells this 'pest'. Your best luck is to find the most shady, unhealthy looking fish store and ask them for the most dirty water weed they have on stock, and pray the weed is infected with hydras.
=How to Take Care of your Hydra?=
-Conditions Hydras thrive in
The jar of weed put at light shade by day time and preferably close to a lamp by night time will suffice. If the water is from a pond or creek, it is a chunk of hydra's natural inhabitant and it will contains all the things that a hydra will eat. Simply feed that body of water some light, the micro ecosystem will reach some kind of equilibrium.
In case your linear transformation of on the state vector predatory species fail to lay inside the bound of the Eigen vectors of the linear matrix and your species preyed each other to extinction, get a new batch from the creek.
-How to Feed a Hydra?
The water body should contain micro-orgasms that will suffice the hydra's need. However, if you want to see a feeding hydra in action, you can carefully remove the hydra to a separate jar (stock the jar with filtered tap water and let the jar sit in the sun for couple days so we dechloroize the water), put some algae in the new jar, and wait awhile while the hydras establish themselves.
You then need to find little wormies, water fleas, or any smaller animals than the hydra, and drop them inside the new tank. Now you can observe when these small planktons drift past a hydra, it will attack and eat them
Something like this:
Okay it's late and I'm calling it a day, GOod night!
![[image loading]](http://www.morien-institute.org/images/triops_billingsgazette.jpg)
