Butterfly Fish, also known by nicknames such as "butterfly tropical fish" and "butterfly fish for sale," are striking marine fish primarily found in the tropical and subtropical coral reefs of the Indo-Pacific region, as well as the Atlantic and Caribbean seas. These fish are well-known for their laterally compressed, disk-shaped bodies, usually measuring between 10 and 15 centimetres, adorned with vibrant colours like yellow, orange, white, and black, often with distinctive eyespots or stripes that help confuse predators. Their small, pointed snouts with bristle-like teeth allow precise feeding on coral polyps, algae, and small invertebrates. Temperamentally, butterfly fish are diurnal and often seen in monogamous pairs or small groups, defending their territories, which makes them fascinating yet delicate to observe. While they are popular in the aquarium trade in the UK, their specialized diet and coral dependence mean they require careful care and a suitable environment. Their presence is also a reliable indicator of coral reef health, revealing the fragility of their natural habitats. Suitable for experienced aquarists, butterfly fish add a splash of colour and elegance but should be purchased with an awareness of their needs and conservation concerns.