|“||You've never seen a fish like this!||”|
— Meryl, The Fish Emporium
Invisible (or ghost) fish are fish that are known to remain transparent with only a distorted outline revealing their location. When fed, invisible fish will briefly become visible and reveal their appearance before becoming invisible again. They are priced at 30,000 shells in the emporium and their additional notes will state they like stealth.
In The Fish Emporium and fish selection screen, they are shown as a regular fish that are slightly transparent instead of completely invisible to allow the player to see how it looks before purchase.
Assuming January 1st of 2017 is day 1 and December 31st is day 365, fish with the invisible attribute are available from The Fish Emporium on days that begin with an even number and end with a 3 as 3, 23, 43, and so on.