What Fish Are You Eating In A McDonald's Filet-O-Fish Sandwich? - Tasting Table
Briefly

The Filet-O-Fish, introduced in the 1960s as a meatless alternative, has evolved from halibut to Alaskan pollock, illustrating McDonald's adaptability to consumer preferences.
Initially created to cater to a meatless demand, the Filet-O-Fish emerged when franchisee Lou Groen introduced it to compete with other menu items, ultimately leading to its official addition in 1963.
Read at Tasting Table
[
|
]