Tobiko (とびこ) is the Japanese word for flying fish roe. It is most widely known for its use in creating certain types of sushi. The eggs are large, ranging from 0.5 to 0.8 mm. For comparison, tobiko is larger than masago (capelin roe), but smaller than ikura (salmon roe).
Fish roe is particularly high in vitamin B12, an essential nutrient that you must get from the foods you eat, as your body cannot produce it on its own. … Fish roe like masago is low in carbs but rich in protein and healthy fats like omega-3 fatty acids.