Genus Monocanthus refers to a group of fish species having a single spine. The common name for these fish is "filefish," as their tough, sandpaper-like skin can be used to file down rough edges. There are several synonyms for genus Monocanthus, including Alutera, Aluteres, and Setarches. These fish are typically found in tropical and subtropical waters around the world, often in coral reefs and rocky areas. They are known for their unique appearance and behavior, such as swimming with a vertical posture and being able to change color to blend in with their surroundings. Some species of Monocanthus are also kept in aquariums as pets.