Let's not confuse other fish eggs with caviar, the latter is without exemption sturgeon roe. Ikea is probably selling eggs from "farmed" rainbow trout, the bulk category in the fish egg world.

There are a lot of delicious fish eggs out there, I regularly (every Winter) indulge in at least 5-10 different kinds with onion, sour cream and black pepper. Caviar is an added delight but I'd be happy with other fine fish eggs as well.