According to old legends, Wood Elves originally descended from the sea elves, who themselves are the descendents of the Merfolk.
The Sea Elves tend to have a fairer blue or green skin, their ears are finned/winged spines, they they have small gills on the backs of their necks. Most also have more than the average amount of webbing between their fingers. They’re not overly different, but the differences are still apparent. They’re excellent swimmers, and can stay submersed for hours at a time.
Their kind is not seen anywhere on Ghiscari. Most people whose lives consist of farming from birth until death in the same scrap of land they’re born in, probably don’t even believe they are real.