my dumb “headcanon” thing:
the lower on the hemospectrum that a troll is, the more ~humanlike a troll’s appearance and anatomy is. meaning, aradia, tavros and sollux would have blunter teeth (aside from canine mutations which is what they all seem to share?), rounder ears, “humanlike anatomy” (the organ system we all know and love) and etc. trolls higher than them would have noticeable anatomical distortions such as limb length, skull anatomy, melanin pigment in skin, muscle functions and eyes.
feferi and eridan would look the most mutated but be the most idealistic physical features for a troll; their appearances are respected. they’d have fins, gills, webbed fingers and toes, cycloid scales, pectoral fins, operculum, paired nostrils and eyes that function the same way a freshwater fish’s would — for now, since i haven’t done much research on deep water fish (aka fish that can take a ton of pressure that normal freshwater fish can’t). their organs would also include an air bladder, hollow spinal cord, lateral line, pyloric caeca and vent. to put this in a realistic situation, feferi and eridan probably… most likely endure the same sort of ocean pressures that isopods, architeuthis dux/giant squid, eurypharynx pelecanoide/gulper eels and other deep sea ocean biology do. constantly.
i find it funny because crustaceans are a group of arthropods that usually dwell in oceans so i’m sitting here sort of flipping out over what the hell KARKAT would look like. since he’s not ON the hemospectrum. he would fall somewhere between aradia and feferi. but he’s not a sea dweller. argh.
—except trolls would be able to move their eyes to look around, unlike owls. so they’d have eyes like function like cat eyes but LOOK like owl eyes. i don’t know.
trolls are also nocturnal, so their eyes would be able to function in darkness, unless they’re a sea dwelling troll, then their eyes function differently altogether.
i really want to draw fish troll anatomy charts.
ANYWAY THIS IS LONG AND EMBARRASSING byE