Tobiko
Appearance
Tobiko (とびこ, in Japanese) is the Japanese word for the flying fish roe used to create certain types of sushi. Tobiko is sometimes used as an ingredient in California rolls.
The eggs are small, ranging from 0.5 mm - 0.8 mm. For comparison, tobiko is larger than masago (capelin roe), but smaller than ikura (salmon roe). Plain tobiko has a red-orange color, a mild smoky/salty taste, and a crunchy texture. Sometimes tobiko is colored with wasabi (green), yuzu (pale orange) or squid's ink (black).
Masago, i.e. Capelin roe, is frequently substituted for tobiko due to its similar appearance and flavor.
Tobiko is also used in the creation of other Japanese dishes.
Wikimedia Commons has media related to Tobiko.