Where does “Fiisch” come from?

Fiisch (Bavarian) comes from Middle High German visch, from Old High German fisk, from Proto-West Germanic fisk, from Proto-Germanic fiskaz, from Indo-European *peysk-.

Ancestry of “Fiisch”, step by step

Step	Language	Word	Meaning
1	Middle High German	visch	fish
2	Old High German	fisk	fish
3	Proto-West Germanic	fisk	fish
4	Proto-Germanic	fiskaz	fish
5	Indo-European	*peysk-	—

Every word from Indo-European *peysk- →Every word from Proto-Germanic fiskaz →Every word from Proto-West Germanic fisk →