Longnose butterflyfish (Forcipiger longirostris). X-ray of a section through a longnose butterflyfish, showing its long nose (left) and elongated dorsal fin (top). Like butterflies, many butterflyfish (family Chaetodontidae) have dramatic colouration, often yellow and black, and eyespots on their bodies. This species is found on coral reefs throughout the tropical waters of the Indo-Pacific. This specimen measures 18 centimetres in length.