Nymphs

Nymphs are a humanoid species native to the plane of Caltora, with a small population.
While poorer Nymphs are often forced to live on the coast, riverbanks or near other bodies of water, due to their unique physiology. More wealthy Nymphs can comfortably live anywhere, as long as they build small bathhouses into their homes and ride in Water Coaches.

Biologically they are a close relative to Humans. The main differences are in their skin and lungs, and accompanying air bladders.
The skin of Nymphs is slightly shimmering and translucent. Instead of having a thin oil film on their skin, Nymphs have an outer layer of cells that block most elements and particles except water to enter their body through the skin. As Nymphs get most of the water for their body through that process, it is required for them, to be submerged or swimming in water for at least half an hour per day. The clothes that Nymphs wear is almost always treated with an inner coat of wax, as their skin is quite sensitive and quickly chafes.
The lungs of Nymphs are adapted to work with both water and air, resulting in Nymphs not having a drowning sensation. They furthermore have an air bladder they can fill, if they wish to and they can reuse the air in their body for longer. This combined makes them capable of surviving for at least 8 hours under water, without needing to resurface for air.