The Fusilier, Caesio sp., is a colorful perciform fish from the Caesionidae family. It is one of the most active fish among other 23 species in this family. These fish are mostly associated with snapper. They are known to feed upon plankton rather than feeding upon larger prey. The Fusilier is native to reefs and marine sites of the Indo-Pacific region. Cylindrical and streamlined, these fish gcan grow up to 60 cm (24 in). They have extensible upper jaws that can be best used to pick up plankton. Due to their distinct coloration, these Fusiliers are easily located in midwaters. They have a greyish-blue body with a soft yellow dorsal fin. You can also see a tinge of pinkish red on their lower halves. They are called by a lot of names like the Red-Bellied Fusilier, the Redbelly Yellowtail Fusilier, and the Robust Fusilier. They mostly eat zoo planktons. So, if you want to house a Fusilier, always opt for a large-sized aquarium with moderate temperature and lighting conditions and remember they are best kept in groups allowing them to school.