#mermaid anatomy

[shirecorn]

Since your merpeople are descended from fish, do they have pelvises? Are they able to assume a "sitting" position?

They do not have human pelvises, but rather they have operculum and preoperculum that rest in the hip area.

This is a very old drawing so I might update it in the future.

Technically they really should not have a great deal of movement in the area (certainly not 90+ degrees) but I choose to let them bend however they want as an artistic decision. Some of my choices are "I haven't figured out the specifics of how this works but I will one day" and others are "I have figured out that this is impossible and chosen to ignore that fact"

If they do assume a sort of sitting posture, they usually use one of both arms to support their torso and not put all the weight on the hips. So they form a tripod of weight distribution and balance.

If they sat on their tail only, they would likely fall over, as it's not built for that.

While underwater, sitting is less about putting weight somewhere, and more about managing buoyancy. Mermaid swim bladders (and almost nothing else) are in the humanoid ribcage area, so whenever they are at rest, they will automatically bob into an upright position. So "sitting" on the ocean floor is less about propping their torso up, as it is about controlling their swim bladder to be neutrally buoyant so they don't float away.

Only mermaids without swim bladders (be it pathology or evolution) have to worry about weight while resting on the ocean floor. Above the surface, however, things get tricky.

[vcreatures]

Mermaids are high complex creatures. An anatomy that seemingly incorporates aspects found in both aquatic mammals and fish. Despite this vast dimorphism, the internal anatomy is largely shared amongst the varying species with some evolutionary adaptations that may be specie specific such as the Labyrinth Organ.

Bestiary log: The term mermaid, despite it’s intrinsic feminine connotation, holds no gender specific marker when discussed or noted. The vast majority of Mermaid, or Merfolk, species have both males and females. Some with obvious sexual dimorphism, others more subtle. However there are species that are hermaphroditic and even fewer that are single gendered, such as Tritons. 

[walk-the-plank-the-what]

Would mermaids live like animals or do they have more structured society like humans? So maybe they live in underwater houses and stay “inside” more than they go outside? Bc they’re basically sentient people, and humans eventually went towards living inside and having societal structure, so if a merperson were captured and put in an aquarium with fish, that would be like putting a human in a forest enclosure with bugs and mice and stuff instead of a house with plumbing. And by the logic that they treat the rest of the ocean like ppl treat the earth, would they have pets? Bc they probably wouldn’t just have a slew of fish friends unless they were some kind of conservationist or something.

Also, I feel like merppl would definitely need plumbing bc otherwise they just breathe in their own nastiness all day

And maybe they prepare their food in a way comparable but different to how we cook food, so just throwing a few fish into their enclosure for them to eat is like if your captors handed you a live bird and expected you to swallow it whole

And if they do live in societies, idk if they would wear clothes or anything like that, but they would have to manufacture materials that don’t degrade underwater as easily, for both clothing and for buildings and tools, and would human captors be prepared to provide more of those if needed? Or they might just have blubber, or be cold blooded and so it’s meaningless for them to have heat insulation

Also, would they have copper-based blood instead of iron based blood like horseshoe crabs? Bc most fish have iron based blood anyway and bleed red, but idk the specific conditions that allowed for some animals to have copper-based blue blood

But maybe land is the only place sentient life like humans could form due to it being important to survival, bc in the ocean sentient life is mostly octopi or dolphins, and they didn’t need to evolve past that for survival so they didn’t, and so all these questions about if they would have inherited a need for societal structure and houses and clothes are meaningless.

[strawberico]

I've recently fallen back in love with merpeople mostly cuz I've been rewatching my favorite Barbie movies!!! 💋💋💋

This betta fish mermaid

Ik the pretty ones are male but I don't care I wanted to draw a pretty mermaid so ig she's trans💋

[sadclownvibez]

gay mermaids cause i still can't focus on school

[vampboykaz]

What’s this?? More fun species concepts??

Again this isn’t representative of this species as a whole, this is just my version of them for something I’m writing and I wanted to share it with y’all!

Merfolk and Sirens!

Merfolk and Sirens are very similar, merfolk just live in shallow water and sirens live in much deeper water! They’re the same biologically and are compatible for reproductive purposes. If they live together their territory’s tend to intersect in kelp forests! While it’s not common for them to be mates, it’s not impossible!

Their tails can mimic any marine species! Sharks, whales, fish, etc! But they aren’t actually related to these creatures, it’s just imitation! Their tails are also incredibly heavy, often weighing upwards of 200 pounds. They also aren’t mammals! Their upper half looks human but they don’t have nipples or a belly button, they also lay eggs!

Merfolk also don’t have male or female like we do, they all have both parts! They do have gender though, but it’s in presentation not related to parts at all!

Unlike angels they are not compatible with humans! In terms of making a child at least. They can absolutely have sex, it just wouldn’t produce any offspring!

Their genitalia is more similar to humans than anything else in function, but isn’t quite the same. Their penis like appendage is long and thing, sort of tentacle like, much longer than a humans, 10-12 inches, but thinner. It essentially functions like a large ovipositor. They don’t really have anything like testicles, rather something more internal that holds eggs that they lay through the tentacle bit into the “female” part of their partner. The tentacle part remains inside them unless aroused, and under it is a part similar to a pussy, since the male part is what lays eggs, they don’t have any sort of menstruation. It’s just for holding eggs. The receiving partner carries the eggs for a little while and then lays them. Merfolk don’t care for their young so that’s pretty much it- they just leave them lmfao. Fish behavior

The eggs are marble sized and tend to somewhat match the color of the tail of the merfolk laying them.

Hopefully that makes sense- trying to explain how mermaid sex works lmfao

also if the eggs were laid inside a human absolutely nothing would happen and they wouldn’t be fertilized since it’s the female part of a mermaid that does the fertilization

Mermaid skin is also a lot thicker and rougher than human skin, but their underbelly tends to be really soft. Their internal temperature is also super high, not uncomfortably so, but warmer than a humans would be

[revretch]

I saw a post where someone interpreted a mermaid's lower half as being 100% accurate to fish anatomy and that bothered me because like

But if that's where you want your mermaid's butt to be, go on ahead

[albanenechi]

Drawing bases & references #27

someone suggested squid mermaids 🦑🦑

[koifishanonymous]

@havanillas’s rtrn mermaid au has been giving me brainworms chat

[gomzdrawfr]

cw: sea animal death

okok, I've never ran walked home this quick just for some doodles inspired by this and this (if you haven't already, go check it out)

tags u...@on-a-lucky-tide

[twst-hottest-takes]

Tweel Anatomy discussion!

Part 1.

(Ask and ye shall recieve! This will be split up into a couple of parts because this could get long and it's easy enough to break up into pieces. [I definitely wasn't putting this off until the cards officially released.])

For starters I have to say again that I just love the twins and their merforms are so cool. I just want an excuse to gush about them. A lot of this discussiom will involve headcanons and hypotheticals and estimations, so there is your warning to not take anything in this post as law. This post, like pretty much all the others is very opinionated. Some of the fun bits about contemplating the anatomy of a fantasy creature involves drawing the imaginary lines between where the fish parts end and the human parts begin, and where the two become a blur and turn into something completely new. I like to think I strike a balance with my hypotheses, but perhaps others might not feel the same way. This is a post meant to start a discussion, not a fight. So let's see how far down the rabbit hole we can go . . .

Starting with a classic: How big are these guys?

Let's answer Ace's question. (While laughing like middle-schoolers about how that question was phrased.)

Now there is no canon answer to my knowledge so I can only give my best estimation. (Corrections welcome!) I firmly believe that they do not change "size" between their land and sea forms. For all intents and purposes, the twins are being treated as though their heads, arms, torsoes, and pelvic regions are the same size between human and merforms.

BECAUSE EVEN WITHOUT CHANGING SIZE THESE GUYS ARE ABSOLUTE MONSTERS IN THEIR MERFORMS.

I have no real proof of my theory. I simply compared the sprites and scaled the chibis until they had the same head size. Forgive me for not having a better method of measurement. I am not going to try and unravel the live 2D mermodels and I think trying to measure their shadows from their intro scene would be even less reliable. The length of the tail is approximately 75% the length of the rest of the body after where his feet theoretically end.

I didn't do the same with Floyd because I feel that it's safe to assume that he's probably a few cm longer (3-5 cm max) due to his 1 cm height difference when they are in human form. I hazard a guess that only the two of them actually care about that difference in length.

332 cm. (Or around 11 ft for those of us stateside.)

We know they're huge, but tying a number to the length REALLY puts things into perspective. Like it's actually a little scary.

Next: Gill placement.

I am a big fan of the gill slits being around the ribs! Not only do they look cool, but I like that it can be read as a combination of human and eel anatomy in their merforms.

Since they have a humanoid chest cavity, it makes sense that even though they don't have lungs, they may have a muscular structure similar to a diaphragm. By having a muscular system that works passively/sympathetically they could have a "breathing" motion similar to humans; but, instead of taking air in, it simply keeps water moving across the gills to maintain gas exchange.

Benefits of this system include: Being able to sleep (as I would assume merfolk do), and being able to stay in one place (most fish need to be moving constantly to keep their gills working). The ability to be stationary isn't necessary for fish, but for merfolk who have social conventions, even being able to sit still to have a conversation is a boon (unless the world of mermen is built around the idea that no one ever sits still, but I feel like the photograph from Book 3 proves otherwise).

Furthermore, having the gills on the ribs as opposed to somewhere farther up--for example, on the neck--the twins can reasonably stick their heads out of the water without fear of limiting their breathing ability. Though these new card illustrations show that they don't seem to have any problem with having their gills exposed to the air (at least as far as being photogenic is concerned), I can see it being convenient for merfolk to be able to poke their head and shoulders above the water and still be able to breath regularly (which definitely doesn't have anything to do with luring unwary travelers to their deaths. . .nope. . .not at all).

I have seen people say they don't like the choice and that the gills should be on their necks. If that's coming from a place of personal preference and is purely aesthetic I guess I can see it. But if anyone tries to tell me that it's not "eel-like" enough and they need to have the gills closer to the mouth, I will fight you. From a design and functionality standpoint the rib gills are fantastic!

For the last bit of this entry, let's talk about the elephant in the room: THE EEL ABS!

I'd say "don't get me started on this one" but I'm already here and we're already too deep in, so here we go.

Things are about to get spicy!

~They're fine.

Like, as a choice, the inclusion of these muscles is likely just for fanservice points, but it's not an anatomically strange thing.

Come here and I will explain to you a thing:

MERFOLK DO NOT SWIM WITH THE SAME MUSCLE GROUPS AS HUMANS DO!

Once upon a time, (this is going somewhere, just stick with me!) people complained that Ariel, the Little Mermaid herself, was too skinny and not built like a swimmer. People insisted that she not have such a tiny waist and her arms should be bigger. Now I, here and now, should not have to tell the reader why this is so ridiculous to say, but I'm going to anyway~ ARIEL DOES NOT USE HER ARMS TO SWIM! Those who have watched the movie may have observed that she swims like an aquatic mammal. All of her momentum comes from the verticle motion of her tail, and to some extent her abdomen, not her arms. When she turns human, Ariel does not even know how she can use her arms to help her swim upwards and out of the ocean. She struggled without her tail so much Sebastian and Flounder basically carried her to the surface.

In this way, merfolk do not need to have the same type of body as a human swimmer because they are functionally different and some people seem to get stuck on that.

Now returning to Jade and Floyd, again, their arms are not "built like a swimmer's." Once again THEY DON'T HAVE TO BE. There is nothing in all of Twisted Wonderland that suggests they swim with their arms at all. These boys have 5 foot long tails that are probably primarily muscle to propel themselves through the water. The arms are not for propulsion. The tails do the grand majority of the work, but this conversation was started about abdominal muscles so we'll circle back to that now. Unlike other merfolk (as exemplified by Ariel) who swim with verticle motions of their tails, eel-based mermen would swim by making horizontal motions, also primarily with their tails. I do say primarily because the idea occurs to me that there may be situations where the limits of their ability to move might be tested. If a merman built like this wanted to go significantly faster than whatever is "normal" for them, muscle groups higher in the body would get used. Essentially, given Jade and Floyd as characters, I don't find it hard to believe that, at the speeds they swim, they would be using their very human-shaped abdomens to increase their speed. That's a workout, especially for the obliques.

So, in conclusion, I don't think the abs are weird. Gratuitous? Absolutely. But they aren't the anatomical monstrosity some people seem to think they are.

Let me say once more, if you simply don't like how it looks, or the fish abs squick you out and you like to headcanon they don't exist--that's fine. But don't argue with me on the basis that it's not realistic. Mermaids are, after all, fictional creatures and depictions of them tend to be fanciful. The tough conversation comes about when we choose to draw the lines with how realistic we actually want them to be, HENCE THIS ENTIRE POST!

(Laughs like a maniac before signing off.)

Thank you for coming to the first part of my rambling. What should I talk about in the next part?

Other than the throat teeth. We've got a miniature essay about the throat teeth just about ready to go.

Also, apologies if there aren't enough visual guides. I really wanted to get this posted, so if anyone wants me to I can doodle up some more stuff to help with things like the image of the breathing aparatus and swimming motions. I have just not had much time this week.

(Going to fall asleep thinking about how sparkly these boys are.)

[shirecorn]

@lux-lumen Mermaids don't need top surgery because they don't have any breast tissue!

The physical features that mimics human breasts are stretchy empty sacks that can be filled with water. They are deflated when swimming for better hydrodynamics, and can be flat or filled with water when at rest, depending on the mermaid's preference. All sexes of mermaids possess the pouches, their use has nothing to do with the mermaid's gender, nor their reproductive sex.

To learn more about this world, follow @worldofvonder

Originally, mermaids evolved to mimic the beauty standards of humans in their regions. But now, mermaids look however they want without caring how humans think they "should."

Some mermaids happen to fit modern human preferences, to the chagrin of insecure people everywhere. Though many humans and mermaids have successfully courted each other... They are still formidable predators with endless defense systems, should you overstep.

While not human, mermaids are still people. Treat them as such.

Now, do stop laughing.

[bastart13]

How do you imagine hybrids work in love and legends? We've seen elf/humans.

So there are 6 different species and aside from the mermaids, they're all compatable to have children.

I headcanon life expectancy, colouration, and the shape of facial or body features to be gradient traits, so they pretty much randomly combine between the two parents like any other child

Magical traits are probably more binary. So a fairy hybrid child could inherit the eyes, wings, and/or sparkles, or none, with no middle ground. A demon hybrid will usually inherit a faded form of the markings, but they won't always be able to transform or earn horns. Dwarf hybrids might inherit the ability to echolocate vs just having larger ears.

If two species with strong magic have a child, they're more likely to inherit magical traits (e.g. elves and fairies with strong magic vs humans and dwarves with low magic)

Considering the domains are all friendly with each other, I imagine it's fairly common to have mixed ancestry and there's no real taboo aside from the grief of lifespan differences

[wtfforged]

ive been seeing a lot of mermaid zoros lately and i like him and i think that silly octopus that he let cling to him in the jaya arc should be his little-mermaid-flounder-sidekick friend

[fmd-art]

[null-entity]

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