WARNING: This blog may contain romanticized depictions of fictional incest and similar themes for the purposes of self indulgence. This is a disclaimer that I do not glorify or encourage these themes in real life!
for this reason this blog is recommended for +16 only, i will also have some suggestive posts occasionally.
If you wish to view this blog please blacklist any squick ships first, as well as #shipcest if you do not want to see incest, and #grubposting if you don't want to see age gap ships. Occasionally i will post art under #liart. :3
Haven’t been keeping up with homestuck canon since the epilogues dropped, but I just learned that the blind prophet Tiresias (whom Terezi was loosely based on) was apparently transformed into a woman for seven years after an incident where he reacted poorly to watching snakes bang, and I think Terezi should trans her gender after watching cherubs bang. send post
A recent major reveal about Alternian society is its caste system, which is based on its members’ different blood colors. Knowing that Tavros has brown blood, Sollux yellow and Nepeta green, I’m going to assume that blood color corresponds to Trollian text color and shirt symbol color. So I’ll extrapolate that the colors on the Chumproll are the blood colors for all our trolls (except for Karkat, who hides his blood color).
In our world, mammals and land vertebrates universally have the same bright red blood as humans. Insects, sea creatures, amphibians and reptiles, however, sometimes evolve to have different blood colors. Trolls seem to be partially insectoid, as they hatch as larvae from a Mother Grub and have a cocoon stage. A lot of their language and technology is also based around grubs. They’re also split into land dwellers and sea dwellers, meaning some of them may have underwater adaptations. So, trolls already fit into the animal groups likely to have non-red blood.
Different proteins found in the blood of real creatures can cause blood to be red, brown, orange, yellow, green, blue and purple. Pink blood is possible in theory, though no known creatures have it. I think that trolls could mix and match these proteins in various concentrations and end up with any blood color on this spectrum.
Red – As you might know, the bright red pigment in human blood comes from hemoglobin. Specifically, it comes from a ring-shaped molecule called ‘heme’, which holds an iron atom at its center. Heme is crucial to human blood because of its ability to reversibly bind and transport oxygen, which is our blood’s main function. About ~15% of an average human’s blood by weight is hemoglobin, which makes the red pigment so intense – the rest is mostly plasma along with proteins and fats that facilitate the transport of this hemoglobin.
Brown – A dark, cool brown blood color is caused by methemoglobin, a very similar protein. The iron atom at the center of methemoglobin’s heme molecule has one electron fewer than the iron atom in hemoglobin, which makes it unable to bind oxygen. Methemoglobin doesn’t have a purpose in the blood and no animals have it as an essential component of their blood. It’s not harmful in itself, but high levels are an issue as they reduce the space available for hemoglobin, and therefore the amount of oxygen available.
Aradia’s blood is probably about 50/50 hemoglobin and methemoglobin according to this color chart; maybe as high as 40/60. In a human this would cause severe health problems and possible coma, but if trolls’ oxygen needs are only around half as high as humans’, this composition would be absolutely fine.
Orange – Orange blood results from the protein vitellogenin, which is found in all species who reproduce via eggs. It is a precursor to proteins found in egg yolks, which contribute to their orange color. Vitellogenin levels correlate with estrogen levels, and it is transported to the reproductive system via the blood. Cockroaches have transparent blood when their vitellogenin levels are low, but pale orange blood when they’re actively producing eggs and transporting this pigmented protein.
Tavros probably has high levels of vitellogenin in addition to moderate levels of methemoglobin. He might not have specific molecules for oxygen transport, however creatures with low oxygen requirements can survive from oxygen dissolved directly in blood plasma. A bigger question would be why Tavros is producing so many eggs, or has such high estrogen levels compared to other trolls, when all trolls play an equal role in reproduction. It’s possible this is linked in some way to his animal communion abilities.
Yellow – Yellow blood comes from vanabins, which are proteins that bind the metal vanadium, and are near-exclusively found in marine invertebrates known as sea squirts. It’s not known exactly what function vanabins serve in the blood or why sea squirts evolved to produce them – evidence suggests they’re not involved in oxygen transport, but potentially make blood toxic to predators.
Sollux’s blood probably contains very high levels of vanabins, possibly high enough levels that his blood is slightly toxic to himself, which might partially explain his ‘mutant brain’ and the extreme pain he suffers on a daily basis. As his blood is a slightly dirty yellow, he might also have low levels of hemovanadin (a pale green vanabin) and of methemoglobin.
Green – Green blood can be caused by a few different compounds. One is chlorocruorin, also known as ‘giant hemoglobin’, a variant of hemoglobin over 50 times its molecular weight (although this is only green at low concentrations). Another is sulfhemoglobin, which is methemoglobin with a sulfur atom added into its heme ring. The last is biliverdin, which is a broken heme ring without its attached metals or proteins. It’s sometimes present in human blood, and gives bruises their green pigment.
Of these, biliverdin is most commonly found in the animal kingdom. Prasinohaema skinks, Samkos bush frogs, and multiple species of fish all have green blood due to high biliverdin levels. Again it’s not known exactly what benefits this offers them, though infection resistance is one theory.
Nepeta, grimAuxiliatrix and Terezi all probably have biliverdin in their blood in various concentrations, and potentially combined with other pigments – Nepeta might also have low levels of vanabin, while Terezi likely has closer to a 50/50 mix of biliverdin and hemocyanin.
Blue – Blue blood is the second most common blood color in our animal kingdom (after red), and is caused by hemocyanin. This is an oxygen transport protein with a completely different structure to hemoglobin, which uses copper atoms to bind oxygen instead of iron atoms. It is less efficient an oxygen delivery than hemoglobin, so many animals using hemocyanin have evolved different lung structures to maximize their oxygen uptake, something else which might be true of the trolls.
Spiders, scorpions, snails, centipedes, crabs, octopi, and other arthropods and molluscs can all have blue blood due to using hemocyanin for oxygen transport. Spiders and scorpions are especially relevant, as arachnidsGrip is themed after these creatures and has bright blue blood. She, Terezi, centaursTesticle and Gamzee probably all have hemocyanin in their blood, either on its own or in combination with other pigments.
Purple – Purple blood is found in some marine worms and brachiopods, and comes from hemerythrin, another oxygen transport protein. Hemerythrin uses iron atoms to temporarily bind oxygen, just like hemoglobin, but its very different overall structure causes it to appear purple instead of red. A creature with hemerythrin-based blood has very low susceptibility to carbon monoxide poisoning, unlike red hemoglobin-based blood, which is extremely susceptible.
This probably isn’t why deep sea creatures have evolved hemerythrin (although they are not well studied in general), but it might be a factor for the trolls. Near the ocean’s surface, carbon monoxide levels are much higher than they are in the atmosphere, and the trolls with purple pigmented blood are those who live in or near the sea. Gamzee probably has a moderate amount of hemerythrin in his blood, while caligulasAquarium and cuttlefishCuller likely have very high levels. This could help protect them from carbon monoxide exposure.
Pink – Pink blood tragically isn’t found in nature (at least, not in any known species), but it theoretically could be. It’s possible that a protein which uses cobalt or manganese to bind oxygen, instead of iron or copper, would give a creature pink blood – and cuttlefishCuller may well have blood containing such proteins. Of course, there are plenty of other theoretical blood proteins which could lead to blood of all colors of the Trollslum rainbow, some of which might be more effective (and lead to a more consistent troll biology) than the others I’ve gone into here.
So, why do trolls have all these different blood colors? A lot of them appear to have psychic powers, which aren’t found in humans. Their bodies need to enable these abilities somehow, and it’s possible that the different proteins in their blood link to their different psychic abilities. For those who don’t have psychic powers, blood could be involved in defense, protecting against specific predators or diseases they’re more susceptible to without the powers to resist them. Different groups of trolls could also have adapted to different environments on Alternia – obviously, the sea dwellers live in the ocean, but there could also be major ecological differences between, say, Sollux’s city and Terezi’s woods, with their respective blood colors developing to fill those environmental niches.
However, since blood is linked to the caste system, it’s also possible that trolls’ blood is genetically engineered. Alternia has prior knowledge of Sburb, so likely has prior knowledge of ectobiology, including the techniques used to engineer a creature like Bec. If powerful entities on Alternia want to make their caste system seem like it’s based in innate biology, and is therefore immutable, it’d be in their interests to alter trolls’ biology directly. And since trolls are all hatched together in large quantities from a single Mother Grub, a team of genetic engineers would have access to all the new trolls at once as they’re created and hatched. So in a practical sense, this would be easy to achieve with the right technology.
If this is true, it’s also possible that trolls naturally have colorless blood, something already observed in some insects and in the crocodile icefish. Blood without any specific pigment is colorless by default as blood plasma is mostly water, and these animals dissolve oxygen directly into their plasma, with higher volumes of blood and low oxygen needs to allow for this less efficient method. If trolls have colorless blood, then their genetically engineered blood colors might be more like fluorescent tracers – chemicals that aren’t supposed to interfere with their blood’s function, but that allow trolls to be tracked and, in their case, differentiated. The trolls’ genetic modifications would mean that their bodies don’t eliminate these tracers, but continue to synthesize them. Karkat, then, could be a troll who somehow slipped through the cracks as a grub, and doesn’t have any blood color at all.
It’s already been confirmed that yellow blood is lower caste, green middling, and blue upper – so it’s likely that the Chumproll runs in order of caste, lowest to highest. However, as a pure color spectrum, it’s a circle – cuttlefishCuller’s high-caste pink blood is only one step away from Aradia’s low-caste red, and their blood probably has a lot more in common with each other than either of theirs does with grimAuxiliatrix’s green. So even if the trolls’ caste system wasn’t engineered and comes from a naturally occurring difference, it’s still socially constructed, because someone decided that red/pink would be the cutoff between low and high castes. Alternia didn’t have to be that way, and it could be changed.
As the writer and performer of the original song, I decided it was time that I remake this with other talented folks who can actually act all of the trolls (unlike me) and, well, create a version where “Perigee” is pronounced correctly…
That said, I am proud to finally present to you this shiny new version of your favorite Homestuck carol–The 12 Trolls of Christmas!
