Every world in the game has several gemstone fish in it. If you eat these fish, they will reward you with one gem. These fish may seem to be just swimming around randomly, but they actually spawn in the same spots every time. Once you eat a gemstone fish, it may take several hours for it to re-appear again, but it will appear in the same place you found it before. Below are images of every world map in the game, with gemstones marking the locations of each of the fish.
These maps are incomplete! If you found a gemstone fish in a location not shown on the map(s) above, make sure to let us know in the comments below!
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