The Fusilier, Caesio sp.,also known as the Red-Bellied Fusilier, the Redbelly Yellowtail Fusilier, and the Robust Fusilier.  is a colorful perciform fish from the Caesionidae family. They have extensible upper jaws that can be best used to pick up plankton.They have a greyish-blue body with a soft yellow dorsal fin with a tinge of pinkish red on their lower halves.  They mostly eat zoo planktons.  and  they are best kept in groups allowing them to school.