The short-nosed unicornfish is mainly active in daytime, unicorn fish roam in groups feeding on algae. They are closely related to tangs and surgeonfish and can grow to around 51-61 cm (20-24 in). The horn-like appendage between their eyes begins growing when a young fish reaches about 13 cm (5 in) in length, and tends to be a little bigger on males. They are generally not aggressive to each other, but when they do fight they use sharp scalpels by their tails as weapons, not their horns. Their skin is smooth and less susceptible to skin diseases compared to tangs.