Ianthina

In the modern day, ianthina are feared: they are the beasts that lurk under the waves and creep in the dark, but this wasn't always the case. Long ago, ianthina used to be victims--human sacrifices chained to rocks waiting for a hungry god--but no more. Their bodies have twisted and changed to withstand the most bitter cold, the darkest depths, and the fiercest storms. They are, have become, and will be survivors.

## Body Language

Ianthina rely heavily on nonverbal communication. Between fins, lumens, and tails that all act as forms of nonverbal communication between each other, many ianthina struggle to correctly read the emotions and body language of other species. To them, a landdweller's range of expression is flat and limited, which further feeds misunderstandings and conflict.

Lumens are incredibly important to the ianthina, viewed as nearly as integral part of their body as their tails. They're a key part of communication: ianthina can light up at will, and flashing their lumens allows for morse code-like conversations at long distances, without making a sound. They're also an unconscious emotional indicator: antennae and lumens react to emotions. Slow glowing in and out can signify relaxation, while lighting up suddenly can indicate fear or embarrassment.

Antennae tend to be an area of focus and carry a lot of cultural weight in Olitskur. While losing a little length at some point in one’s life is common—antennae are able to regenerate if the tip is lost--to lose ones' antennae entirely is akin to losing an arm or similarly brutal sort of mutilation. Antennae curled toward the face can indicate interest and curiosity, while antennae pressed back against the skull can indicate fear or disgust. Because of how they're used for communication, and because they're relatively delicate, touching an ianthina’s antennae without permission is extremely taboo. For most, it’s an act of intimacy reserved only for parents, lovers, and the very closest friends.

Ianthina fins--including their tail fin--is also another avenue they tend to use to communicate. The cartilaginous rays in fins allow the fin to flatten or flare. They might flare their fins when angry or excited, puffing up bigger, and might flatten their fins, bringing them close to their body, when they're scared or shy. Ear fins are mobile and can collapse down on each other or separate further when flattened of flared. Due to the muscles that control the rays being close to the body, ianthina with long fins have much more difficulty expressing themself this way, since their fins react more slowly to the movement of the rays.

Much of how ianthina move and communicate can be compared to cats. They're jumpy, and sometimes, they scurry. When on land, they'll drop to all fours if they think they'll need to make a quick getaway, or if they're trying to be cautious in how they approach something. Their pupils respond to emotions, expanding or contracting when they're excited, interested, alarmed, etc. Ianthina can also chirp, hiss, growl, and purr.

## Coloration

An ianthina’s skin tone is the primary color of their body. It can be any color of the rainbow, but these colors always are muted, either pastel, dark and muddy, or somewhere in between. There are no ianthina with brightly colored skin.  Skin color is genetic and acts much like paint mixing: if a red-skinned and blue-skinned ianthina have a child, that baby will most likely be purple-skinned, although it can be anywhere on the red-blue gradient. For this reason, most city-dwelling ianthina are somewhere in the human range of skintones (aka brown). Primary colors are most commonly seen in the Southern Enclaves and small towns, where a more limited population allows those colors to reemerge.

While ianthina are typically solidly colored, a number of conditions can cause this to not be true, including but not limited to: vitiligo/piebaldism (white spots), port wine stains (non-glowing spots in a darker shade of their lumen color), blaschko lines (dark stripes), pityriasis alba (pale spots), freckles, scars, and other causes of skin markings. Ianthina also occasionally display mottling, where their skin tone is uneven and darker in places. These are the general trends, but every so often, you see markings in every shape and size. The one thing that is always consistent is that the skin is de-saturated, allowing their lumens to shine brightly.

Most commonly but not always, the base color of an ianthina's fins is very similar to its skintone. However, colors can appear vastly different due to the present of accent colors and lumens. Lumens always appear on the fins, permitting them to glow, and their coverage can range from a thin line on the very edge to covering the whole surface area. Lumen coloration on the fins can also show up in a wide variety of patterns, from gradients, to spots, to stripes, and more. If it appears on natural fish, it could potentially appear on an ianthina. Occasionally but not commonly, some ianthina also display unique accent colors on their fins, brighter colors not seen elsewhere on the body. Lumen color can also affect the central part of the tail.

Ianthina can have any hair or eye color.

## Diet

While ianthina are capable of eating a wide variety of foods, they are ultimately obligate carnivores. Predictably, most of their diet consists of fish and assorted other marine life; there are few animals that they consider off-limits. There is very little plant life in the oceans, but they are capable of eating and digesting most plants. To suit this diet, they have fangs, sharp molars, and claws on their hands and feet.

## Lumens

"Lumens" collectively refers to all the parts of an ianthina that glow: the antennae on their foreheads, the spots on their skin, and the edges of their fins. Lumen color is unique to each ianthina, influenced by a complicated array of genetics. It also colors their blood a deeper, richer shade of their lumen color. These spots can be found all over the body, but they tend to cluster on the face, shoulders, thighs, and fin edges. The different types arise from mutations in their spots. Freckle-types are standard. Spotted-types have extra large lumens, thus glowing brighter--a boon for others, but occasionally too brightly for the ianthina who has them. Ring-types are closely related to spotted-types: it's as if the spots never got filled in, for a more normal level of brightness. The thin edges of star-type lumens means they glow a little dimmer, but not significantly. Constellation-types have thin, misshapen spots that give the appearance of the constellations. Constellation-types also tend to have fewer lumens overall, making them slightly dimmer. The typically-thin lines on stripe-types means they tend to have a dim glow as well. The brighter an ianthina glows, the warmer their bodies are.

### Toxicity

The chemicals that provide lumen coloration and make them luminescent also happen to make ianthina mildly toxic. This toxin doesn't spread through skin-to-skin contact, but it is found in their flesh and bodily fluids, to varying degrees. Generally speaking, this doesn't impact an ianthina's daily life. It's only a problem if you're a shark trying to have an ianthina for lunch; fellow ianthina are immune to the toxin. That said, the genetics that cause lionfish fins happen to be linked to an ianthina's toxicity, and lionfish-type ianthina are far more poisonous than average. The toxin in their saliva means that, if they bite you and break skin, contaminating the blood stream, you will become ill on top of whatever damage they do. Fortunately for landdwellers with lionfish ianthina lovers, the effect is far less potent if exposed to their saliva through, say, a kiss. At worst, an extended makeout session may result in some numbness and a tummyache.

## Respiration

Ianthina are amphibious, with two frilled pseudo-gill slits located on each side of their necks. While these slits do indeed have gill filament to assist breathing while swimming, the principal function of these slits is actually to drain excess water from the lungs after an ianthina surfaces. The diaphragm compresses the lungs to expel the water; gills absorb oxygen from the water as it leaves via the slits; and the newly emptied lungs are able to intake oxygen.

Because of their gills, ianthina are particularly sensitive to smoke and other airborne irritants.

## Skin and Fins

The skin of an ianthina is soft and almost dusty to the touch. The oils their skin produces are extremely hydrophobic, which allows them to form a very thin, protective layer in water. This layer means that their hands won't prune when they're underwater for long periods, and it protects them from bacteria and other damage osmosis might cause. Most ianthina can be underwater their whole lives, never surfacing, with no issues. The layer also means they tend to dry fast.

Ianthina fins are thin, delicate, and soft to the touch, almost satin-like. On top of their back, arm, ear, and tail fins, they have webbed fingers and toes. They don't have many nerve endings in their fins, so they're not particularly sensitive. For this reason, piercings are extremely common. In Olitskur, back fin piercings, close to the skin, are typically given at a young age to allow wetsuits to be buttoned (or snapped or tied) up. Fins can regenerate small holes or tears, but they cannot restore major damage. If tears are quickly stitched, they can heal, but if an injury is left too long, or kept open (as is the case with piercings), it will become permanent. Ianthina are capable of becoming infected with fin rot, and that can also cause the edges of fins to be eaten away, exposing the rays.

Thin cartilaginous rays allow fins to flatten or flare at will or in response to emotions. Thicker rays are what form spiked fins, and separated rays are what form lionfish fins. All ianthina are slightly toxic, due to the chemicals that make their lumens, and the lionfish gene is closely tied to much, much higher levels of these toxins.

## Tails

Everything mentioned about fins also applies to ianthina tails. Their tails are flattened, like rudders, and very powerful and muscular: the tails provide most of their forward motion when moving in the water. The fins on their tails catch water, pushing it aside in a side-to-side motion. The rarer the tail, the less effective this process is. Bifucated, short, and long tails are notably impaired in swim speed. Long-finned ianthinas in particular tend to have trouble. Their fins are easily targeted by wandering predators, and it's extremely common for their fins to become tattered or acquire holes as they age. Because of this, in Olitskur, long-finned ianthina are typically viewed as beautiful, fragile, and delicate, regardless of their actual personality.

## Vision

Ianthina are nocturnal, and their eyes are adapted to pierce the dark depths of the ocean through long months of arctic night by the thin light of their lumens, and thus are extremely light sensitive. Their irises can come in any color and tend to be relatively large, to maximize the size of the pupil in the dark, and their scleras are black. Their irises are capable of expanding and contracting to an extreme degree, either expanding so much to leave the pupils mere pinpricks, allowing them to function in slightly brighter environments, or contracting until the iris itself is scarcely visible.

Star- and W-shaped pupils are by far the most common in Olitskur, as they are the most effective at seeing through the dark. String-of-pearl and ray pupils can't expand as wide, making those who have them (by ianthina standards) borderline night blind and struggle to navigate outside cities. These types of pupils are the most common type in the Southern Enclaves, as those ianthina live closer to the surface in generally brighter environments. Bar- and heart-shaped and pupils are somewhere in the middle: they can handle light better than star-shaped, though not as well as string-of-pearl, and can handle darkness better than the string-of-pearl, but not as well as star-shaped.

They have a third eyelid, to protect the eye while swimming fast and to clear away any debris.