#biological immortality

[bethanythebogwitch]

Last week on Wet Beast Wednesday I covered some of the biggest animals ever so this week I'm going to do a complete 180 and talk about the smallest animals in this series so far. Not so small as to be micro-animals (I'm sure I'll get to tardigrades eventually) but pretty small. Meet the hydra, a genus of freshwater cnidarians that can be found in temperate and tropical water worldwide. There's a lot of neat stuff about these tiny critters. Such as the fact that they're immortal, but we'll get to that in good time.

(image id: several hydras attached to a rock. Each hydra is a long, anrrow tube that branches at the top into 4 or more thin tentacles. They are milky-white in color. Source: Jan Hamrsky)

Hydras are visually similar to tiny anemones, but they're more closely related to siphonophores and jellyfish. Their bodies are pretty simple, consisting of a tubular body. On one end of the body is the basal disc, a simple foot that adheres to substrate. On the other end of the tube is the mouth, which leads into the gut. Ringing the mouth are tentacles that are covered in stinging cells. The gut is pretty simple and like other cnidarians, it doesn't go all the way through. That's right, when a hydra poops it comes out the same way it went in. A typical hydra consists of 50,000 to 100,000 cells and I hope for their sake that none of them are used for taste. Hydras are diploblastic, consisting of two layers of cells. For comparison, all vertebrates are triploblasts, with three cell layers. The hydra's layers are the epidermis on the outside and the gastrodermis making up the gut. Separating the layers is a gelatinous matrix called the mesoglea that functions as a hydrostatic skeleton. Hydras can contract their bodies and will do so if disturbed. When fully extended, they reach no longer than 10 mm (0.4 in). Hydras are in the cnidarian subphylum medusozoa. Other animals in this subphylum go through two stages of their lifecycle, a polyp that attaches to some substrate and a free-swimming medusa. In most, the polyp is a larval stage that will metamorphose into a medusa during maturation. Hydras instead stay as polyps their entire life. This could be a form of neoteny, the retention of juvenile traits into adulthood. Like other cnidarians, hydras are radially symmetrical. What is most impressive about hydras are their regenerative abilities.

(image id: a drawn diagram of a cross-section of a hydra with labeled anatomical features. source)

Hydras are masters of regeneration. It is this trait that earned them their name, a reference to the hydra of Greek mythology, who would grow two new heads whenever one was severed. Chop a hydra in half and each will grow into a new hydra. Chop a hydra into many pieces and you will get many hydras. Their regeneration is so impressive that if you chop one up into many cells and put them next to each other, the cells will reassemble themselves back into the original hydra. Similarly, hydras primarily reproduce asexually through budding, where one hydra will grow a new hydra out of its body. The daughter hydra will eventually split off from the parent and go on to live independently (unlike certain people I knew in high school). The daughter hydra is a genetic clone of the parent. A hydra living in good conditions can make a new clone every few days. In some species, sexual reproduction is also possible and usually only done when conditions are poor. Depending on the species, individuals can be either hermaphrodites or dioecious (either male or female). Gametes are released into the water to fertilize. Imagine if you wanted to make a baby and to do so you took a handfull of sperm or eggs and threw them all over the place, hoping that someone else also did the same thing in the right time and place. Broadcast spawning is weird.

(image ID: photos of a hydra in the process of regeneration. The hydra is green. It is cut in half, creating a head and foot end. Additional photos taken over time show each end growing into a new hydra. source)

(image id: a pale white hydra growing a bud. the bud emerges from below the head and appears as a small tube. The head of the tube is branched into 5 small nubs that will grow into tentacles. )

Hydras are predators that feed on insect larvae, tiny invertebrates, and small enough fish larvae. They use their basal discs to attach to a hard surface like a rock or branch and extend their tentacles into the water. When something brushes against the tentacle, it triggers the stinging cells. These stinging cells are called nematocysts. Each nematocyst can release what is essentially a tiny harpoon that injects neurotoxin into the target. Nematocysts fire so fast that the harpoon can experience up to 40,000 Gs of pressure. Because nematocysts are tiny, an animal that touches a tentacle will be injected with venom from many of them, getting poisoned even more as they thrash about and get tangled up. The tentacle will then transfer the prey to the mouth. Hydras can swallow pretty large prey, expanding and contracting to fit the prey animal into them. It's kind of like a snake swallowing an egg bigger than its head. While typically sessile, hydras can move around. They can slither around on their basal discs, but when they need to move fast, they summersault. When summersaulting, a hydra will reach down and grab the ground with its tentacles. It then detaches the disc and moves it to a new position. This repeats until the hydra finds itself in a good spot. A speedy hydra can move a food few inches in a day. Hydras can also secrete gas bubbles from their basal discs to float around, upside-down, in the water. A hydra will usually only move from its spot in response to pressure such as predation, competition, or lack of food.

(video: a video of a hydra capturing and eating a mosquito larva. It starts with the mosquito touching a tentacle, which adheres to and stings it. Once the larva is dead, the hydra pulls it in and gradually engulfs it. Despite the larva being larger than the hydra, the hydra can stretch its body to fully swallow the mosquito)

So about that immortality thing. Yeah, it's not just that hydras can regenerate from just about anything, they also don't age. They're kind of like Tolkien's elves in that while they won't die on their own, they can be killed. No undying lands for hydras though. As far as we know. It has been found that hydra stem cells can infinitely renew the body, preventing the effects of aging. This means that a hydra living in a place with no threats could theoretically just keep going forever. They can still die due to predation, disease, starvation, poor environment, and all the other usual suspects. We actually know the gene sequence responsible for this. I tried to read up on it, but genetics is way over my head and it literally game me a headache trying to read. Along with their longevity, hydras also have an incredible ability to repair damage to their DNA. This is important as damage or mutations in DNA accumulate with age. This is why cancer is primarily a disease of old age. As damage accumulates past the body's ability to repair it, eventually a mutation that causes cancer will come along. The longer you live, the more time this mutation has to occur. The hydra's ability to repair its DNA keeps them from all inevitably getting cancer. Naturally, scientists are hugely interested in hydra regeneration, DNA repair, and immunity to aging. If we could figure out how these things work and apply them to humans it would be huge. Expanded, perhaps even indefinite life spans with reduced effects of aging are obvious, but there are other applications. Better DNA repair could vastly reduce the chances of getting cancer or other genetic conditions while regeneration could potentially allow people to regrow limbs or organs. This is obviously still in the realm of speculation, but it's exciting to think about. In conclusion, all hail our immortal overlords, the hydras.

(image id: a hydra growing on the shell of a dead snail. The hydra is a pale yellow color and contracted, causing its midsection to bulge out. A bud is growing from one side of it. Source: Jan Hamrsky)

#wet beast wednesday #hydra #hydra animal #hydrozoan #cnidarians #biology #zoology #ecology #freshwater ecology #freshwater biology #aquatic biology #biological immortality #immortality #regeneration #not like doctor who #Youtube

[seablazar]

#dailyseacrits #jellyfish #turritopsis dohrnii #immortal jellyfish #biological immortality

[heintzmagic]

#Biological immortality

[metapatrickism]

Patrick Ludlow Carol Williams & Biological Immortality

#PatrickLudlowCarolWilliams #Biological Immortality #Patrick Ludlow Carol Williams #MetaPatrick #MetaPatrickism #PaleoPatrickism #Helperanthropyism

[rainymoodlet]

the main cast of the joy of life legacy, generation three 🦇

rowan krueger, heir 👑 / ???, known as alsace dieudonné, ancient (ancient ancient) vampire and resident of forgotten hollow

ivory krueger, gen 2 heir and rowan’s mother 👑 eva capricciosa, rowan’s mom / cassandra goth, rowan’s mamá

jax krueger, spare, eva and cass’ baby / sachiko sasaki, ivory’s half-sister

dallas krueger-sasaki, founder 👑 shingo sasaki, ivory’s nanny and dallas’ soulmate

vladislaus straud, founder of forgotten hollow who allows alsace to hide there, perpetually disappointed / damian cross, vlad’s husband-bloodbag-sugar baby thrall turned immortal soulmate

seraphine straud, damian and vlad’s daughter and sole heir of the straud fortune / ivan bloodvein, head chair of the council and seraphine’s devotee-husband

mina, tomas, and verana bloodvein, seraphine and ivan’s triplets, little anklebiters who vlad utterly dotes upon

#ts4 #ts4 cas #ts4 screenshots #;tjol+ #;tjol #sim tags later dhdhdh #|| #the halloween edit will be late 💀 i was late to work bc of this but it was WORTH IT #i love them all so much it was so WEIRD to age them all fhdhhd #might make dallas and shingo immortal bc i just can’t deal with their passing but also WEHHH PLOT #i am so excited to get back into playing this legacyyyy #gonna break the curse of the third generation y’all!!! i swear!!! #i will not force mpreg upon y’all though dhdhd but rowan can biologically have bebs #alsace is so cooool i can’t wait to get into his lore!! #sachi and jax turned out SO STUNNING i’m so besotted with them both #the moms are all older now and i’m 🥹🙏 #if rowan actually disappeared like he will (cough) they’d go to war so he’s actually #going to be backpacking across windenburg with low cell coverage but #he goes to forgotten hollow :)) little lyin’ ass boy #WORK IS A MESS RN i can’t WAIT to change jobs omg #haven’t heard anything yet but 🤞 #hoping!!!! #love y’all MWAH 💋

[itty-bitty-sunshine]

im curious, how did perkeo become immortal? you say theyre the dont age dont die type but theyve still aged to the point of an average adult. so was there a point where they became immortal? were they born immortal but still aged to the point where they seemed like the average human then stopped?

this is a bit more morbid but im curious about this too

how severe can injuries get if they cant die? how does their body handle situations where the average person would bleed out? would they heal faster? would they just have infinite blood? what if they got into a coma? would they ever wake up? or is it just not possible? how would they heal from injuries that would make it impossible for the average person to come back?

if youre not willing to answer the second stuff thats fine, im just really curious

They do not remember

The earliest memory they have is on the kingdom, and they were already a grown person by then

They remember kneeling, the agreement made with the king

They remember tests, and them stopping with lack of results

They remember doing their job afterwards, and the years that went on as they remained the same

They remember making people smile and laugh and how they cherished that feeling more than anything

That does not mean they never had a family, though

Morbid details under cut

Very. They had to crawl their way out of things no human could even dream of surviving, things no one should have survived — or even lived enough through it as it happened

They can still get dizzy, they can still faint, things can go to black, but eventually their brain will pull them back awake again. Die, but come back

The wound would close, but they can bleed out. They can feel the dizziness, the cold, the pain. If severe enough, they could pass out — either until the wound closes or until their brain decides it gotta keep fighting still. That said, they very likely could deal with a stab wound without passing out if outside factors are not included (if anything, they would just be annoyed)

Sewing a wound would likely make it close faster than leaving it alone

Their heart would always start beating again even after stopping, so I guess you could say they have infinite blood?

They would wake up from a coma I'm pretty sure (how long it would take would depend on the cause), unless it was like, medically induced (which would mean constant upkeep to keep em like that) because yk. Strong drugs

They do heal from injuries that would be impossible for a normal person to survive. Their body puts itself back together – and when it can't, it just makes a new part to compensate

So, for example: let's say they get decapitated. They could put the head back on the neck, and the body would work to glue the two together again

Now, let's say they lost a leg and for some reason could not try to put the leg back in place: then the body would make a new leg. It would take a lot longer, and be infinitely more painful, but it would be back in place one way or another

(Now for what happens to the lost limb — idk it probably rots as the body regens. They are already immortal, might as well throw some nonsense in the mix)

How can they grab their own head and put it back? Idk that's too much to keep track of. Maybe magic who knows

Also! Burned skin will heal and fade, take that was you will

Essentially I would say it's just kind of nightmarish but they do heal pretty fast (how fast? Idk, but pretty fast), and that they would also be pretty used to some level of pain rn

#dont worry im more than willing to talk about this kind of things #surprisingly i thought a lot about it because i wanted it to be more biologically-based than just magically and painlessly fixing yourself #though theres still some holes where and there that i could not fill #whatever angst i could throw into this story i did #this au is deep wounds disguised as hope and never ending search for a better ending #they had to crawl their way through hell. but they will have their happy ending #its the least they could have after creating them for so many people #dca au #immortal au #immortal au ask #cw mortality #cw: gore #tw gore #cw loss of limbs #cw amputation #graphic depictions of violence #cw graphic depictions of violence #cw character death #cw medical trauma #(?) #idk putting it just in case #cw decapitation #cw blood #blood #im not good with cw so if theres anything else i should put please let me know and im so sorry in advance #cw coma #?

[aquaquadrant]

if it’s just the double life cast.. please tell me we’re gonna get a little side impdubs content 😭

PERHAPS

#hels to pay au #HTP ask #in case it wasn’t clear in part 4 i’m going for a double life poly impulse-bdubs-etho-joel kinda vibe #but like it’s chill #i imagine most relationships are really casual and change from world-to-world without like #being a dramatic Thing #some players form deeper more lasting connections #but that doesn’t always mean they’re strictly monogamous either #players are functionally immortal beings that don’t reproduce the old fashioned way (they’re all made by the universe yknow) #so biologically speakin there isn’t a HUGE drive to remain monogamous their entire lives #ANYWAY. yes i am an ethogirl. yes i luv me some impdubs. we exist

[xehanortsreport]

ansxig :)

#sorry for who i am i will continue to be like this #immortality that can only exist by taking from others fascinates me #and a relationship built on two different types of immortality interacting with each other is so neat #add in the complications of the various dynamics...a bodyguard who's technically more experienced #but prefers to take orders and be led. and an ambitious younger immortal who is just beginning to hit #his second adulthood. the thin line separating xehanort and ansem is experience. #and also just biologically...being a heartless. the Only sapient heartless...that's horrifyingly lonely #and being from an era long forgotten...is also terribly lonely. #their isolation is so unique that even their isolations cannot fully be resolved with each other #but in a post kh3 world maybe they could try.

[startistdoodles]

Gonna see how well I can properly tackle this question since it is rather loaded xD Time for a biology lesson-

Firstly, they are not completely immune to viral infections/sickness. While uncommon, they can still get sick in various different ways (colds, flus, migraines, etc) but in most cases they won’t die from it. But not all illnesses are created equal; dark matter poisoning is incredibly likely to be fatal to a puffball. And it can cause body parts to rot in areas that are affected by it when left untreated.

Injuries sustained from weapons do have a chance at killing, but it depends on the injury. Intense wounds obtained in battle are more likely to result in death rather than sickness.

#they have biological immortality #anon #ask #not art #kirby worldbuilding #injury mention #death mention

[quercus-queer]

This the shit I’m talking about when I say I want to be immortal like bitch??? The continents are MOVING a new ocean is forming and I want to see the world change in every way imagineable like the earth is so amazing why would I want to leave. I hope I get to be ghost floating around the world exploring 😭

#geology #plate tectonics #my beloved <3 #immortality #ur telling no immortal bitch has ever been absolutely STOKED to see the geographical changes along with humanity??? are you kidding??? #all the biological changes all the CHANGES THE CHANGES BRO U ONLY GET TO SEE LIKE 80 YEARS IF YOURE LUCKY LIKE PLEASE

[theshalesky]

Living beings have only 2 possibilities to make their species survive in the long run: reproduce or become immortal. What if there was a human-like species where evolution had chosen the second option? If the species always consisted of the same beings, who had been alive for at least thousands of years? What if that species still slowly became extinct, because there's no way of being truly immortal - and over time, one by one, they got killed by the inescapable forces of nature?

What if this species decided to find a way to artificially create descendants - but they didn't quite get the immortality right? What if the being they created was incapable of dying, but their flesh was still slowly rotting from the inside?!

#idk if this is completely biologically accurate #but since i've heard that immortal single-cell organisms exist i'm kinda obsessed with this idea #and yeah... the idea of rotting from the inside is weirdly relatable and comforting to me #i'm hesitant to post ideas like this on here because i might turn this into a novel one day and now it might get stolen #but whatever #writing #writeblr #writers on tumblr #writing prompt #story ideas #fantasy #immortality #the last part could be the corruption from tma ...

[salvadorbonaparte]

Is it weird that I'm sadder about my local post office guy having a terminal illness than my (biological) grandfather having a (potentially) terminal illness?

#I say potential because from what we heard it's pretty bad this time but also #He survived several cancers strokes and heart attacks because that bastard is immortal apparently #I say biological grandfather to differentiate him from my grandpa

[just-random-shitposting08]

Fyodor might be a tree

#cause the only biologically immortal thing is a tree #haha get it #bungou gay dogs #bungou stray dogs #fyodor dostoevsky #bsd fyodor

[mitriwww]

Idk how to explain this properly, but these two are giving me the same vibe

#tf2 #tf2 sniper #hercules #they both adopted lol #and basically immortal #they literally came back from death just to kick some ass #the only difference between them is that Hercules's biological parents are not that shitty and his adopted parents are still alive ig

[mumblesplash]

which trigun show would you say someone should start on?

depends on what you like i think? if you care a lot about visuals and can easily connect to characters without needing to feel like you Know What’s Going On you’ll probably like stampede, if you care more about plot and like. a more tangible-feeling sense of story and worldbuilding it’s probably best to start with the original

#splashasks #agendercryptidlev #iirc you followed me for danny phantom so you’d probably fall into the first category #mood wise tristamp almost feels like if dp was canonically as horrifying as the fandom made it but still sorta kept up the cheery facade #the characterization so far is actually really good but half of it is like ridiculously subtle and it hides behind the obvious #like there’s a part where vash refuses to kill and eat a bug even though he’s hungry and like #yeah that’s just What He’s Like and you already know by this point #but the way it’s set up in context is actually a really clever nod to the fact that vash is biologically immortal #bc to him if ‘it’s gonna die soon anyway’ was a good enough reason to not care about something he wouldn’t care about humans either #AND the bug is conceptually connected to a child he failed to protect in the previous episode #its a blink and you’ll miss it type of thing and also the much more blatant reference to his pacifism and self-destructive tendencies #feels like it could feasibly be the whole point #also stampede has way more vashwood and way less vashmeryl #but there’s no milly thompson yet and milly is delightful

[romeo-the-homeo]

begging sam to turn me so i dont have to have this cold anymore

#i assume vamps dont get ill cause like the healing and biological immortality and that #redacted audio #redactedverse #redacted sam #sam collins