I'm playing through Pokémon Sword and trying to fill up the pokédex. For completionist sake, I want to catch both forms of Gastrodon - The East Sea (blue/green) and The West Sea (pink/brown).
So far, I have encountered three locations where I can catch Shellos/Gastrodon, but I have only ever encountered the East Sea form.
Where can I find a West Sea form of Shellos/Gastrodon in Pokémon Sword? Are they version exclusive?