Double-lined fusilier (Pterocaesio digramma)is also known as the Twinstripe Fusilier and the Two-stripe Fusilier Fusiliers are fishes in the Caesionidae family. They are related to the Snappers but have adapted to eat plankton. Their proportionally small jaws and teeth are suited to picking planktonic matter out of the water out of the water table. They have deeply forked caudal fins. They congregate in large shoals often comprising several other species of Fusiliers and are fast swimming. They patrol the reef at high speed and will often circle around divers. At night they separate and hide on the reef. Gold Sash Fusilier (Caesio xanthalytos) is also known as the Yellow Sash Fusilier Fusiliers obtain their name from their bright colours and the fact that they move in formations. When they were named this was characteristic of armies in Europe at the time.