For Science: Building a Better Hydra

[Lord Dusk]

So...guys... my fiends and I came with some interesting Hydra scenarios that we would like to debate.

What happens if you decapitate a hydra but only cauterize part of the wound?

If you decapitate the Hydra at the base of the skull, do two new heads grow from the single stump, or does it sprout neck extensions?

what happens if you were to split the hydra perfectly evenly down the middle?

what happens if you break the neck of a hydra but leave it otherwise intact?

Does hydra blood clot?

where in the sam-hell is the extra mass coming from????

[super dark33]

Breaking the neck of the hydra is neglected by its regenaration i think.

Splitting the hydra perfectly...
Each half uses the other half as reference and as aid to regenarate two heads.

Cauterizeing only part of the wound.. i think it would regenarate itself back to non-cauterized and then back to two heads. so it takes more time to grow the heads.

Cutting the base of the skull is a tough one.
I think two heads grow from the cut, thus makeing the head look like a snake's tongue.

I dont quite understand the last question.

These are my thoughts.

[Asta Kask]

I think your first mistake is using science... :smallamused:

[Lord Dusk]

I dont quite understand the last question.


which one?

Hydra blood was supposedly mildly acidic and poisonous in the original myth. This would make it difficult for the blood to clot a wound.

Growing additional heads would require more mass, but as the fallen heads are not reabsorbed and the hydra does not seem to change in mass, one must wonder if it grows progressively more hollow as it grows more heads, digests itself, or other variation.

[Lord Dusk]

I think your first mistake is using science... :smallamused:

BAH! science and magic are interchangeable, so long as you designate one of the two as your primary set of laws and disregard any instances where it contradicts the secondary laws. What is an artificer if not a magic engineer, or an alchemist a magic chemist? :smalltongue:

[The Succubus]

Hydra biology? Interesting subject choice.

I think the first thing you would need to do is reclassify it slightly. Developing extra heads and regenerating nervous tissue and especially the vast amount of bone would be almost physically impossible.

Instead, we should look at a hyrda as being more closely related to say an octopus or sea anenome. The hydra would have a central nervous cluster somewhere within its main torso that serves as its "true brain". After all, even when all its heads have been served, a hyrda is still very much alive. The heads may have some rudimentary sub-brain, similar to that found in a halfling, with ganglions dedicated to things such as sight, smell, taste but I would think that the true concious thought processes go on in the true brain.

Now, looking at some of the other stuff:

Cauterisation - at best, a brief road block. Remember that cauterisation in humans is largely used to stop excessive blood loss and prevent infection. The way the celluar regeneration process would work in a hydra - being fast enough to rebuild a whole limb in in under a second - any scab formed by burns would rapidly be healed and then broken through by the sheer mass of cells underneath it.

Half a hyrda - I'm guessing this would result in a dead hyrda. After all, you'd be splitting several critical organs in half, like the heart, lungs, true brain. While a hyrda may be able to handle blood loss from the neck for a minute or so, I'm fairly sure the blood loss, shock and trauma from being split in half would be fatal.

Broken neck - As the tissue is intact, I would guess that the limb with a broken neck would not divide or regenerate but instead eventually wither off the main body. Couldn't say whether it regrows afterwards.

[Lord Dusk]

Hydra biology? Interesting subject choice.

I think the first thing you would need to do is reclassify it slightly. Developing extra heads and regenerating nervous tissue and especially the vast amount of bone would be almost physically impossible.

Instead, we should look at a hyrda as being more closely related to say an octopus or sea anenome. The hydra would have a central nervous cluster somewhere within its main torso that serves as its "true brain". After all, even when all its heads have been served, a hyrda is still very much alive. The heads may have some rudimentary sub-brain, similar to that found in a halfling, with ganglions dedicated to things such as sight, smell, taste but I would think that the true conscious thought processes go on in the true brain.


Excellent points, but one still has to wonder where the mass that it is using to generate these pseudo-limbs is coming from.
Additionally, the 'necks' could easily be disguised tentacles, but the 'skulls' are still capable of delivering crushing bite attacks, so would have to be made of a strong bone-like material. Possibly condensed cartilage?
They would also have to have enough nervous connections to control both the tentacle-limb and and optical nerve, since they seem to be able to see using the 'heads'. it is possible that they don't see at all and rather use some form of sense not readily apparent to mortals, such as psionics or something we've yet to come across in evolution.

[Eurus]

Excellent points, but one still has to wonder where the mass that it is using to generate these pseudo-limbs is coming from.
Additionally, the 'necks' could easily be disguised tentacles, but the 'skulls' are still capable of delivering crushing bite attacks, so would have to be made of a strong bone-like material. Possibly condensed cartilage?
They would also have to have enough nervous connections to control both the tentacle-limb and and optical nerve, since they seem to be able to see using the 'heads'. it is possible that they don't see at all and rather use some form of sense not readily apparent to mortals, such as psionics or something we've yet to come across in evolution.

If we continue with the octopus comparisons, the heads might be similar to tentacles in that they move almost autonomously, without direct concentration on the part of the main creature. That would also mean decapitated heads continuing to flop around and bite for a while. :smallamused:

We know that D&D hydras do have their regeneration stopped by fire or acid. Pyro- and Cryo-hydras are also capable of releasing breath weapons, which in a normal animal would almost certainly consume far more energy than it could recover by hunting. So it must have some other source of energy. Honestly, I can't think of any alternative but to call it Magic. Some part of the hydra presumably absorbs magical energy, or siphons it from the elemental planes, and converts it into the energy and mass required to heal.

[super dark33]

which one?
.
this question


where in the sam-hell is the extra mass coming from????

[The Succubus]

If morally-dubious science ever manages to create a hydra (fao: morally dubious scientists - get cracking, damn it) we would need to be more realistic with our expectations:

1) Hydras would have to have a maximum number of "limbs". As the comic pointed out, our hydra still has a finite amount of blood and evolution would have seen off hydras with too many heads, be it through starvation or predation when they collapse from lack of oxygenated blood.

2) Hydras must have absolutely incredible heart muscles. Think about a giraffe - it has a heart 2ft long and weighing in at 11kg (thank you wikipedia). A human heart by comparison weighs 350g and is approx 10cm long. I stuck my head into the cardiology dept next door to get that info and my friend offered up a very interesting fact - there are no creatures that have more than one heart, although the heart may be divided up into several smaller organs (such as in octopuses and squid). We now have to take blood pressure into account.

2a) Now, with our hydra, we cannot have one normal heart such as humans have. Lets say our normal hydra starts with eight heads or so, with a vascular system designed for it. If we start lopping heads off left right and centre, the sheer force of the blood coming out of it will cause it to take off like a bottle rocket. So, what we would need to do is have one central heart, like the central brain, with a smaller accessory heart at the base of each neck.


EDIT: Lord Dusk, can you do me favour and change the thread title slightly - "Building a Better Hydra" or something like that, so that biology Playgrounders can offer their insights as well? =D

I'm getting a real kick out of this thread so far.

[Lord Dusk]

this question

Growing additional heads would require more mass, but as the fallen heads are not reabsorbed and the hydra does not seem to change in mass, one must wonder if it grows progressively more hollow as it grows more heads, digests itself, or other variation.

[Lord Dusk]

If we continue with the octopus comparisons, the heads might be similar to tentacles in that they move almost autonomously, without direct concentration on the part of the main creature. That would also mean decapitated heads continuing to flop around and bite for a while. :smallamused:

We know that D&D hydras do have their regeneration stopped by fire or acid. Pyro- and Cryo-hydras are also capable of releasing breath weapons, which in a normal animal would almost certainly consume far more energy than it could recover by hunting. So it must have some other source of energy. Honestly, I can't think of any alternative but to call it Magic. Some part of the hydra presumably absorbs magical energy, or siphons it from the elemental planes, and converts it into the energy and mass required to heal.

So, on the first count, we have a potentially deadly decapitated limb, still capable of movement and attack... unnerving, it's like a zombie's limb that tries to strangle you...

On the second count, it has a magical organ similar to a dragon. Does this potentially mean that it could have all of the elemental-based abilities of a dragon, such as the ability to diffuse themselves into the land upon their death?

[Ulysses WkAmil]

Idea on Mass Regeneration:
-The Hydra may have an organ that takes elements out of the air, such as
CO2. With a little fission, fusion, and cell reconstruction, you get flesh. In this regard, the Hydra may need to be related to some form of predatorial plant, as CO2 consumption is kind of a plant thing. Now take this, couple it with a massive stomach and enormous appetite, and bob's your uncle. The Hydra could use food or even waste material as a reconstruction agent if it had an organ like this. Cell communication/organization for a Hydra would have to be phenominal, almost unreal though.

-Since I'm only a sophmore in highschool, I'm not to certain this is physically possible, but if it were, the internal heat generated from the atom splitting/bonding may explain something else.

-Also, I'm not sure if you could break a Hydra's neck, if we are relating the beast to an octopus or starfish. Regenterating bones thick enough to break would take unrealistic amounts of time. Not to mention its calcium intake. 'twould need to live near a dairy pasture! :smallamused:

-I believe cauterizing only part of the wound would leave live cells at the end signaling for regeneration, causing matter and such to build up the neck hole

-No idea on clotting factors. Haven't touched that subject yet.

-Last note: Why are we finding legitimate means of creating the worst predator ever known? For fun? I love it regardless :smallbiggrin:

[Lord Dusk]

Yep, this is fun! every played plague inc?

Out of curiosity, does anyone know how a gecko regrows it's tail? :smallconfused: this could be an accelerated version of that...

[The Succubus]

Yep, this is fun! every played plague inc?

Out of curiosity, does anyone know how a gecko regrows it's tail? :smallconfused: this could be an accelerated version of that...

A quick trip to wikipedia reveals the culprit - stem cells. While I could accept stems being quite capable of regenerating neck and skull tissue, regeneration of eyes, nasal tissue and things like tongues would be considerably more difficult, especially if we're considering extremely rapid regrowth.

I think we also need to start considering our hydra's diet as well. All of this regeneration is going to require an absolutely monster amount of calories, so a hydra will either have to spend most of its time making successful kills of extremely large creatures or spending a lot of time dormant.

It's worth remembering that a hyrda won't be spending all of its time regrowing stuff, so a certain amount of food will be able to be stored as body fat. Also, adventurers will not be a natural part of a hydra's diet, so it wouldn't need to regrow heads too often. Maybe one or two depending on the size of prey and the success of a hunt.

Given its reptilian nature, it may be able to preserve energy through a cold blooded respitory system, and warm itself in the sun each day, similar to iguanas and the like.

[Asta Kask]

Idea on Mass Regeneration:
-The Hydra may have an organ that takes elements out of the air, such as
CO2. With a little fission, fusion, and cell reconstruction, you get flesh.

Carbon dioxide content of air: 3.9*10^-5 g/liter. That's some powerful concentrators there.

[Brother Oni]

(fao: morally dubious scientists - get cracking, damn it)

Technically speaking, nature beat us to it (http://en.wikipedia.org/wiki/Hydra_(genus)).

The original Lernaean Hydra was a water based critter, so its vast bulk would be offset by simply staying submerged most of the time. I like Eurus' suggestion of a magical organ deriving additional energy from an elemental plane to power the regeneration and supplement normal basal metabolism, so it probably wouldn't need to eat as much as you'd a expect a creature of that size would.

The reptilian basis for physiology would also help, although it would make it more akin to a crocodile rather than an iguana.
Speaking of crocodiles, imagine if a hydra adopted more of that animal's hunting patterns, primarily an ambush predator. That many attacks and a surprise round sounds suspiciously like the beginnings of an accidental TPK.

[The Succubus]

Hmmm, I'm not keen on this magic mumbo jumbo as a way of building our hyrda. I prefer a scientific or at least psuedo scientific way to do it.

So we've agreed that simple caloric intake from eating won't be enough to sustain our hydra - we need another source of energy from somewhere. Photo-synthesising scales may be one solution, especially if we're going with a reptilian metabolism. That said, even plant-based photosynthesis still requires nutrients to be drawn up from the soil, so it'd still have to work in tandem with a normal digestive system.

Perhaps some way of generating electricity (biological nuclear reactor!) may provide the missing energy we need.

[Asta Kask]

If you can build a biological fusion reactor maybe...

Still won't solve the mass problem, though.

[Ulysses WkAmil]

What about a period of hibernation, similar to a mammal, but the Hydra eats X times the amount of its body weight to be stored as regenerative material? And it would hibernate in muddy bank-soil so it could absord nutrients and generate extra carbs?

Now it really feels like we're just making Super-Aniplantimal. I don't believe the accelerated regeneration via stem cells can legitimatley explained, so I guess that goes in the "Nessecary Psuedo-Science" folder. Unless it created some sort of amphetamine-like chemical that boosts cell communication to unrealistic lengths. Like that guy who ran 1,000 Miles on nothing but meth whilst escaping an African army. Or something.

[Lord Dusk]

so, we have at the moment concluded that our megabeast needs these aspects:


centralized brain in main body
centralized heart in main body
photosynthetic scales
a stasis period, triggered by consuming X amount of sustenance during which it absorbs nutrients from the soil
limb "heads" which equate more closely to ocipi tentacles.
said limbs use cartilage to construct pseudo-bone skulls
predatory patterns similar to a alligator or crocodile.

[The Succubus]

Nononono, we don't need to draw nutrients from the soil. My post said that some of the nutrients drawn through the normal digestive processes can get an extra boost from photosynthesis.

Possibly the photosynthesis process converts certain sugars and fats into starches, which may help during the hydra's hibernation periods. I really think we need to steer away from turning this thing into a plant.

So three basic templates -

Reptilian - Because hydras are reptilian in every depection I've seen of them, plus the whole slow metabolism + hibernation stages.

Cephlapodian - The multi-limbed thing with added heads.

If we're going to be using cartilage, there may be some form of aquatic ancestor in our hydras past. After all, sharks have an exoskeleton comprised of cartilage.

While the photosynthetic scales may help with energy issues, as stated above, it's not a freaking tree or plant, so let's be vaguely sensible here.

[Brother Oni]

Unfortunately there is no way to use scientific or even pseudo scientific means for the regeneration.

The fastest cell cycle I know of is 10 minutes and that belongs to a micro-organism. There's nothing that I know of that can even hope to replicate the hydra's mythical regeneration and certainly not differentiating into specialised structures like skin, bone muscles, etc.

As for photosynthesising scales, they need to be paper thin and/or translucent, so that the sunlight can penetrate. This in turns makes the critter very fragile, thus making it unlikely to engage in physical combat, completely counter to the legends of the hydra, which was a very aggressive, highly poisonous creature.

I'm also not sure why you require additional nutrients from the soil - photosynthesis just requires carbon dioxide and water as raw materials, assuming the chloroplasts are in place already.
The problem is getting sufficient carbon dioxide to the photosynthesising cells - normally this wouldn't be an issue in an animal with a circulatory system as the carbon dioxide would be bound up in whatever oxygen fixing molecule it uses (or just dissolved in the blood stream), however we've decided to make our hydra reptilian for the reduced basal metabolism, which in turn has the side effect of it not having very much circulating bound carbon dioxide in its blood to give to its photosynthesising cells.


@Ulysses WkAmil

I'm not following you on why an amphetamine based substance would be useful here, given it's a neurotransmitter stimulant and wouldn't be of much use in the cell signalling system for repairing damaged tissue.
There's also the issue of how the hydra is storing the extra mass. Storing carbohydrates would be useful for the energy demands of regeneration, but you need amino acids to supply the raw building blocks for tissues, not to mention whatever materials it needs for the bone.

I'm not aware of any biological mechanism that stores amino acids though since most animals biosynthesise what they can and ingest what they can't, so your hydra will be packing large fat stores as that's usually what excess protein is converted to.


TL,DR: Magic organ supplying energy and mass from an elemental plane is much easier to rationalise.

[Ulysses WkAmil]

Bad use of term on my part: I meant a chemical that would speed up cell communication/regeneration, akin to the way amphetamines speed up humans activities. Forget the weak analogy, and I'm not even sure if such a chemical exists. Just spitballin'. I'm about 98% unbacked theory here, I'm at day 22 in sophmore biology :smallsigh:

Also: Yes, I oversimplified the idea of storing biomass. Back to the ideaboard. I think we should subtract bones from the neck, would a felxible spinal cord work? And I do agree magic organ is easy to rationalize, but I'm with Succubus. We should rule magic down to last resort.

[Worlok]

My sort-of-take on how a Hydra might get sufficient energy to fuel its regenerative abilities, strictly speaking as a curious layman here:

I seem to remember several translations of the original myth featuring some manner of large crustacean that lived alongside the big H and actually came to its defense. And while this might be a bit of a stretch, I'm thinking the answer may lie in some manner of symbiotic relationship with other species.

It, as in the Hydra, is commonly depicted as a swamp-based creature, meaning it's unlikely to ever not be exposed to full sunlight. No deep water, as such. Even though Lerna's a coastal region. But I digress - Could it be possible for a Hydra to live in symbiosis with some manner of moss or algae that cover its skin and somehow satisfy some of its energetic needs out of leeching off photosynthesis? Not a biology buff, honest question here.

I kind of imagine a creature that size being basically something of its own ecosystem to a degree - Algae live on Hydra, draw algae-eating things, drawing bigger things that eat algae-eaters, potentially drawing yet larger things (e. g. human-eating monster crabs), and those big things are what the Hydra (normally) eats (when on land). An apex predator that is also a living deathtrap, essentially.

Alternatively: Lerna being a coastal region, as mentioned before, it could perhaps also be that it's an ocean-going mega-predator, along the lines of the Kraken, except from another mythology - and the one Herakles ran into was an aging or disoriented one far off its native territory, like a beached whale, essentially. That then became a threat due to suddenly being cut off from its normal prey - actual whales maybe? It would kind of allow the Age-of-Mythology-style approach in which Hydra and Skylla are implied to be closely related species (same God, etc.) to take, which I think is nice (and don't worry, I recall just enough mythology to know/think/be fairly certain that they have quite prohibitively different background stories in that regard, technically).

Come to think of it, and working off Kraken / giant squid similarities... whales having lots of fat and blubber in their bodies, they are the kind of energy-rich food that, far as I'm aware, could maybe allow a Hydra to be possible. And regenerating in the first place would likely be a defensive mechanism that caught on when sperm whales rolled around and proved good at biting off tentacles / snake-like necks.

What do you guys think? This sound sensible? :smallredface:

[Eurus]

Perhaps it eats the severed heads after battle to recover some of the energy...

[Ravens_cry]

Well, if the brain isn't actually in the heads, it could regrow them, over time.
Many creatures after all can regrow limbs and tails. Cauterizing the wound as done by Hercules could certainly slow the process.
But the instant regrowth? I see that as being basically impossible at least with biology.

[Ulysses WkAmil]

The brain being in-body or on a central, much larger head would be best I think. That way we can make each head a sensory organ container+feeding tube, rather than an actual head. Much faster regeneration.

[Ravens_cry]

The brain being in-body or on a central, much larger head would be best I think. That way we can make each head a sensory organ container+feeding tube, rather than an actual head. Much faster regeneration.
Well, since hydra are basically animal intelligence in most stories I am aware of, certainly in the original myth, the central head doesn't need to be really any larger than than how it is usually presented. False heads that don't even contain sensory organs but act as decoys could cut down on regen time, especially if they also don't contain bone. One reason bone takes so much longer to heal is because it uses plasma rather than red blood cells to supply oxygen.

[zlefin]

perhaps extra heads aren't actually regenerated, but are simply stored in the main body (which tends to be quite large and round, good for volume storage compared to a relatively thin head).
Then when wounds occur extra heads are simply pushed out; there'd be a limit at some point obviously.
It might not be evolutionarily sound, but when you have crazy scientists like us and/or gods creating it; having spare heads stored in the interior would be feasible.

[Absol197]

perhaps extra heads aren't actually regenerated, but are simply stored in the main body (which tends to be quite large and round, good for volume storage compared to a relatively thin head).
Then when wounds occur extra heads are simply pushed out; there'd be a limit at some point obviously.
It might not be evolutionarily sound, but when you have crazy scientists like us and/or gods creating it; having spare heads stored in the interior would be feasible.

For the D&D version of the hydra, this works well - remember, they can't have more than double their original number of heads, and the extra ones wither and die after 24 hours. Maybe it stores the extra heads in combat so that it can fight it's opponent more effectively, then reflexively withdraws any over its normal number slowly after it stops fighting, to prevent it from needing extra energy keeping them going.

That way, it can take several days to regenerate the lost heads - it just grows them back inside its body, instead of on the outside.

Also, the central head with an actual brain is supported by the myth, or at least some versions that I've read. I recall that in many versions, the central head was immortal, so Heracles couldn't cut it off and burn the stump, so he just trapped it under a rock instead.