#not like doctor who

[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)

[kotse]

@hg-aneh your honor they’re silly

edit: i am NOT aneh!! i love and have borrowed their character designs, no affiliation!!

[nat-20s]

name a more iconic thing to happen for the fictional qpr community than Donna Noble quite literally meeting her soulmate and being like hmm. there's no one I've ever wanted to fuck less

[nipuni]

Phoenix

A speedpaint video of this will be available at my Patreon soon 😊

[lastoneout]

"Violence only leads to more violence" TRUE! The thing is tho, a lot of people in power seem to think the start of the violence was the CEO getting shot, but they're wrong. The start of the violence was that very CEO running a company that turns immense, endless human suffering into money.

Violence did lead to more violence, decades of needless death and suffering willfully enacted by millionaires so they can make just a little bit more money, that was the start of the violence. If they didn't want it to escalate eventually, they should have maybe not made killing people the core functionality their entire company hinges on.

The people being tortured and killed by the health insurance industry are not the ones who started the violence, and tbh I don't really think it's on them to end the violence, either.

[myiliterallyhavenolifegoals]

Learn your history!!!!

[mwagneto]

aint no WAYYY THEY JUST TRIED TO SAY THAT. not even "the doctor's" but doctor who's in general 💀💀 so now that they have a disney contract every single gay thing (which they've had for fucking decades) is gonna be a huge big huge first gay thing ever!!1!1!1!! event??? like yeah there's a very specific significance to it i get it but what the fuck do you mean😭 jamie pull up the files

[doctorhomo]

“old man writes about gen z on their damn phones” ?????? no?????? old man writes about the dangers of staying in your own bubble and prejudice and privilege to the point where you’d rather die than let a black man save you????? old man writes about useless influencer-types who are so dependent on their bubble that they dont know when they need a piss???????? old man writes about white people desperately trying to make their own aryan society and staying in their racist BUBBLE ????????

[g3othermal3scapism]

rose tyler visiting home wearing tshirts from artists and tours that havent happened yet or tv shows that dont exist yet and everyone thinking she just has weird obscure music taste and is rly weird. its 2006 rose tyler walking down the street and everyone who glances at her shirt is thinking ‘who in the fuck is olivia rodrigo and where did this girl get a 2024 tour shirt’

[alternativeulster]

dont let anyone ever tell you the doctor who tv movie (1996) sucks. this is literally the best scene in all 60 years of doctor who

[benisasoftboi]

Best thing about Doctor Who, and I mean this so genuinely, is the way it goes from ‘haunting Celtic folk mystery about death and penitence’ to ‘what if your group chat banter was so dire that your phone developed sentience and tried to kill you’

[biggest-gaudiest-patronuses]

main take aways from Halloween (1978) rewatch:

michael myers is canonically 21??? this bitch should be at the club

*sees tiddies* ***MURDEROUS RAMPAGE NOISES***

that's it that's the movie

outside of the fact that everyone who has sex is murdered by the narrative, this is a surprisingly chill portrayal of female sexuality? these teen girls are horny and actively enjoying Getting It On with their boytoys. no pushy boyfriends sneaking in through their bedroom windows--these ladies are taking the initiative to sneak out and GET SOME. one of them gets laid and then immediately orders her boyfriend to get her a beer. (yes she gets Slashered soon afterward, but so does the boyfriend so honestly, gender equality.) yes the Final Girl is the only one not having sex, but she's not bullied for that, nor are her friends slut shamed except possibly by being murdered by the narrative

actually the only character who is shown being morally condemned on-screen is michael myers. specifically FOR his violent overreaction to other people's sex lives. (people he is spying on). metaphorically, the villain is American Puritanism sticking its judgy nose into other people's business.

aka Michael Myers Is A Republican

but actually the real villain is the doctor. guy's a judgemental, shaming, pathologizing asshole. and he's been in charge of michael's care since he was SIX YEARS OLD? kid never had a chance. i'd go on a killing spree too

also the parents. where are the parents? it's halloween night and all the teenage girls are home babysitting their younger siblings? come to think of it, michael's first victim was his own older sister, whom he killed while she was babysitting him. teen girls are really shouldering a labour burden here. maybe parentification is the true villain

side note: mike commits his first murder wearing a clown costume...which is never referenced again? his 'iconic' costume is a generic mask and wig and jumpsuit, when we coulda had a Killer Clown Michael Myers??? travesty

i like how the Final Girl and her friend casually smoke weed in her car. yeah she's an honor student and her friend is the sheriff's daughter. yeah they smoke weed. so what it's 1978

(to reiterate, mike is 21 and should be at the club. im not saying he shouldn't be rampaging, im saying it's sad that he broke out, tasted freedom for the first time in his life, and immediately snuck back into his childhood home to go rampaging. let's have a remake where he goes to a nightclub and has a few beers. maybe some slutty dancing. then rampage)

oh no he's hot

[causalityparadoxes]

Cannot emphasise how OBSESSED i am with the Doctor being able to hear the show's backing music. Does he have favourites? Does he ever miss the funky classic who tunes?

Its giving Day of the Doctor novelisation, where the Doctor's vision changed when the show's colour grading did.

I love whenever they make allusions to the 4th wall or skirt near it. 1st Doctor talking to the people at home. 4th Doctor's laugh at the camera. 12th Doctor's monologues and playing of the Theme tune. Its all so wonderful.

But to put it in the forefront. To literally have him say " I Thought that was non-diegetic " (music not actually present in the world and only for the audience) to have him WINK at us.

Obsessed is too weak a word for what I'm feeling right now. I love them

[image description first image: The Fifteenth Doctor with an expression of surprise saying, "I thought that was non-diegetic." second image: The Fifteenth Doctor looking directly into the camera, about to wink. end description]

(Thank you @thevalleyisjolly for the image description text!)

[nat-20s]

Ten and Donna end up on a fucked up deadly space newlyweds show despite uh. Not being newlyweds but they get almost all the questions right. They start to sweat when the final question is "what's one secret desire you have involving the other?" And Donna writes "sometimes I wish I could occasionally shrink down the doctor real small so I could carry him around in my pocket and make sure he doesn't get lost' while Ten writes "sometimes I wish I was small enough that Donna could carry me around in like a cat backpack or maybe a shirt pocket" and they look at each other like AYYYYYY because not only are they deeply drift compatible they're also fuckin weird about it 💖

[nipuni]

Overflight 🌃

A speedpaint video of this will be available at my Patreon soon!

[expelliarmus]