Merkid's evolution is gender dependent: Female Merkid evolve into Mermarine and male Merkid evolve into Mersidon, both when exposed to a Shiny Stone.
Biology
Physiology
Gender Differences
A female Merkid has coloured Pink, while a male Merkid is coloured Blue.
Special abilities
Behavior
Habitat
Game data
Pokédex entries
Pokédex entry
They were once believed to be myths until their discovery in Rainbow Reef. Moving in schools, they would hypnotize people with their voices and make them leave them be.
Their older designs had them more fish-like and they also had a different face and appear to have a collar or frill on them.
Merkid is one of the only Pokemon in Solar Light to be in a branched evolution line, with Baawool and Guppish being the other 2. Unlike Guppish and Baawool, Merkid can be captured in the wild and is a Gender based evolution, similar to the canonical Pokemon, Burmy.
It's name is similar to the name of a Fakemon from Pokemon Uranium.
Origin
It is based off a Mermaid. The ears might hint that they they also based on elves. The Shell on their heads forming a crown shaped hair clip is a reference to princesses and princes.