fish eggs on sushi rolls

spheres on a sushi roll? The spheres on a sushi roll are usually flavored or plain fish roe, and they go by a few common names: Common Types of Spheres on Sushi Rolls: 1. Tobiko (とびこ) 2. Ikura (イクラ) 3. Masago (マサゴ) 4. Spherified Sauce or Juice (Modern Sushi)