The distinction between caviar, tobiko, and ikura is because they are all the roe (eggs) of different species of fish, therefore their flavors, textures, colors, and sizes are all different. Apart from flavor, the most noticeable distinction is that tobiko and ikura are more commonly seen in Japanese restaurants, whereas caviar is more commonly found in fine dining establishments.
“Traditionally, the name caviar refers solely to roe from wild sturgeon in the Caspian and Black Seas,” according to Wikipedia.
The majority of the time, I’ve seen caviar used as a garnish on top of a meal (so don’t expect to see people eating it by the spoonful). The eggs are tiny and black in appearance. Caviar may also refer to a type of fish egg; the size of caviar varies based on the species of fish. The majority of caviar I’ve seen is black.
Tobiko is the roe of a flying fish. Sushi restaurants are the most popular place to find these. They’re generally red-orange in color (not to be mistaken with masago, which is smaller and brighter), although they can also be green, red, or black. Tobiko is normally served as a garnish, although it can also be requested separately. Depending on the restaurant, you may get tobiko or masago when you see “flying fish eggs” without the Japanese name next to them. Tobiko is my preferred tobiko over masago. Tobiko is somewhat more crispy, and the roe provide more of a tactile component and have a more distinct taste since they are larger.
Salmon roe is known as ikura. Individual roe have a more unique flavor than a single tobiko or caviar, in my opinion. I’ve tasted ikura that was sweet, salty, and fishy. They look like a little version of popping boba to me. Salmon roe are much larger than tobiko or caviar, and I used to refer to them as “the giant fish eggs” when I was younger. Here’s a side-by-side comparison of ikura and caviar:
Tobiko is the roe of a tropical flying fish, and it’s prized as a sushi topping. Ikura is a Japanese fish that is frequently served as a garnish on various varieties of sushi, either alone or as part of a larger meal. It’s made out of brined salmon roe, or salmon eggs, that have been separated into individual eggs, however many are usually served together. Caviar is the roe of a sturgeon.