From PIE *pisk- — Latin 'piscis' shows the same root, with the p-to-f shift explained by Grimm's Law.
A limbless cold-blooded vertebrate animal with gills and fins, living wholly in water.
From Old English 'fisc,' from Proto-Germanic *fiskaz, from PIE *pisk- (a fish). The word is one of the oldest and most stable in the Germanic languages. The PIE root also produced Latin 'piscis' (fish), which gave English 'Pisces,' 'piscine,' and