Hydra model system 🤩

Hydra model system 🤩

Amongst all the different model systems maintained in CUBE HBCSE Lab, one of them is HYDRA…As we all know the STEM has started few months back but there’s no topic particularly on Hydra… Before starting with objectives,first let’s get a bit in touch with what are hydras? Where are they found ? What do they feed on ? How to culture them ? etc.


Hydra are a genus of small, fresh-water organisms that are classified under the phylum Cnidaria.They have tiny, tube-shaped bodies that contain several tentacles on one end. They are native to the temperate and tropical regions. Biologists are especially interested in Hydra because of their regenerative ability. Hydra has a tubular, radially symmetric body up to 10 mm (0.39 in) long when extended, secured by a simple adhesive foot called the basal disc. At the free end of the body is a mouth opening surrounded by one to twelve thin, mobile tentacles. If Hydra are alarmed or attacked, the tentacles can be retracted to small buds. Below is a picture showing how a Hydra looks.



When food is plentiful, many Hydra reproduce asexually by producing buds in the body wall, which grow to be miniature adults and break away when they are mature. Below is a picture of Hydra life cycle.



Well, at present in HBCSE lab there are very few hydras left maybe around just 30-35. There’s a serious need to culture them, otherwise we would be losing a model system from our lab :cold_sweat: so I have started culturing hydras too, so as to increase their number.

OBJECTIVE:- To culture Hydra as their number is very less.


Culturing hydras is too easy,
:point_right: Firstly I took 5 250 ml beakers.
:point_right: I had put ~100 ml of declorinated water in each.
:point_right: I had put 3-3 hydras each from a Hydra beaker culture present in HBCSE lab.
:point_right: Now after putting hydras, I had put ~12-15 colourless moinas from a moina bottle culture with a help of dropper.( Moinas-as a feed for hydras…each Hydra feeding on 3-4moinas per day as observed).


These are the 5hydra beakers which I prepared today itself and each beaker is having 3hydras each.

This is just a new beginning…need to know many more things about hydras… hopefully I could save them from being vanished.

@arunan @g_n @drishtantmkawale @akshita @jaikishan @ritikbhaviskar @lydia @bunny @virenvaz @jtd and all , please put in your inputs and views on hydras…what all experiments can be done with them ? How to identify a particular specie ? Does Hydra sleep ? etc.


What about Tank culture of Hydra, why no mention about it?
How often are you planning to feed these beakers?
What is your expectation?
Why not take some good photos of hydra from your culture @Sjuday2527?

Why not look for budding in your cultures of hydra?

What are studies which are done on hydra, as it is a well known model system?

How are you planning to culture hydra?
@Mohd.Arifshaikh has inputs on this

Do you need method to culture hydra?

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Isn’t this a method ? What according to you mean by method ? @mohd.arifshaikh


We can also do regeneration studies with hydra as this system is very simple .Try cutting the hydra and see which parts regenerate the entire body with tentacles

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According to me mean by method is protocol to culture hydra


Yes so that’s what I have stated in my post @mohd.arifshaikh aren’t you convinced with my protocol? Please share your protocol too if you have better than this.


Ma’am actually all the people in Hydra group as far as I know here in CUBE are doing only regeneration studies (amputing them and checking which part grows and why ?) ,There is no other study being done except this on Hydra …this is the only reason I asked all of you to put in your inputs and we all can start a new study on Hydra .


Are you talking about this :point_down::point_down:protocol??
Protocol to culture hydra:
Step 1: Take approx 80ml De Chlorinated water in a 100ml Beaker.
Step 2: With the help of droper transfer hydras in that Beaker.
Step 3: Feed moinas to hydras by the ratio of 2:1 i.e 2 moinas per hydra by dropper
Step 4: After that by muslin cloth cover the beaker.
Clean the beaker everyday by removing the debris (dead moinas) using a dropper.


I would like the names of people in charge of Hydra model system and the location of CUBE with which they are coordinating for the wiki of all model organisms that we have at CUBE.

Check the wiki at:


@Sjuday2527 why not look at literature and find out what all studies can be done with hydra?
As we have hydra culture we can develop it.
Are there any stem cell research which can be done with simple model like hydra?
Can we understand areas like cancer with this simple looking organism?


How does the hydra sense it’s prey? is it by olfaction or water motion or light or some other method?





@Deven @apurva


Simple and brain storming question sir :clap::pray: will read about it and will revert back …

Hydra are members of a family of radially symmetric animals (Cnidaria), all of which use specialized cnidocytes (cells present on their tentacles) to catch prey. This family also includes well-known creatures such as jellyfish and corals, which, like other cnidarians, have the simple design of a mouth surrounded by tentacles. Hydra tentacles contain barbed, poison containing cnidocytes that they use to stun animals like the water flea, Daphnia , before eating them alive, and to protect themselves from attack by other animals.


But is it only light?

In which case it should fire cnidocytes every time there is a passing shadow, a very energy wasteful process.

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Sorry sir but can you please explain this, I didn’t get you :sweat_smile:

Sir Hydras have very thin tentacles that drift with the currents and sense any movement that touches them. But I don’t know what is causing such movement and how… Ithink when there is any change in the water current , the cnidocytes present on the surface of tentacles sense the intensity of force which has now changed because of the change in water current. So maybe based on the intensities which the cnidocytes are sensing they may react to it.

This is just a mere thought,


The opsin protein is sensitive to light. So whenever there is change from light to dark or vice-versa it will react. However a change in light intensity in this case a reduction in intensity is not a guarantee of passing prey. If the hydra keeps firing it will waste a lot of energy.

What experiment can be designed to findout the hydra’s mechanism of identifying prey?

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