The yellow longnose butterflyfish or forceps butterflyfish, Forcipiger flavissimus, is a species of marine fish in the family Chaetodontidae. The yellow longnose butterflyfish is widespread throughout the tropical waters of the Indo-Pacific area from the eastern coast of Africa to Hawaii, Red Sea included, and is also found in the eastern Pacific Ocean from Baja California to the Revillagigedo Islands and the Galapagos. It is a small fish which grows up to 22 cm in length. This species can also be found in the aquarium trade. Being territorial, yellow longnose butterflyfish patrol their patches of coral with a monogamous partner. However, instances of overt aggression among F. flavissimus have been observed between territory holders and individuals of the same sex. Chasing is rare, but when it does occur, males chase males and females chase females. Females defend food resources from other females, while males defend territories containing a female from other males. (Source: Wikipedia.org, CC BY-SA)