These are invaluable knife skills to know, even if you don’t wish to skin and fillet the fish yourself. I do like to do it myself, since I can then have the bones to use in stock - getting more value for my dollar!
This can also be used with fresh sole, uh, which I happened to see whole, on ice over at Whole Foods yesterday. Hmmmm. May have to nip back over there.
Play the video at SD or slow speed, otherwise it will drive you nuts.