Editing Ianthina (section)

== 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 helps them dry out faster. 

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.

This is all assuming the ianthina lives primarily under water. Adjusting to life on land can be quite difficult for ianthina. Many have issues staying properly hydrated: they may not recognize the sensation of thirst, not know how to alleviate it, or be able to gauge how much they need to drink. They can also struggle with dry, flaky skin. Live out of water long enough, and their fins will toughen slightly, feeling more akin to a bat's wing or a snake's skin.