Primarina is a Selkie

selkies are scottish/irish fairies (fary type)
they are seals that turn inyo people (water type)
they are often categorized with mermaids and sirens (singing motif/theme)
selkies can be male (and apparently are quite seductive)
apparently female selkies make good wives. let's NOT google that...
stories about selkies are usually romantic tragedies (there are lots of pictures of sad poppios saying do you love me?' coincidence? maybe not...)
go watch the movie 'Song of the Sea'. it's cute. and the barn owls could be rowletts.