[6] Territoriality is commonly displayed by benthic-feeding longnose butterflyfish, therefore, because their main dietary resources fulfill these characteristics.

[7] Although several could cause a species to evolve monogamous behavior, the necessity for biparental care does not apply to longnose butterflyfish because they lay pelagic, or freely floating, eggs.

One source of selective pressure responsible for the monogamous pairs observed could be the advantage of territorial defense it provides.

[4] Besides the advertisement displays accomplished through monogamous pairing, territorial domination by longnose butterflyfish has also been observed by means of acoustic behaviors, which provide important cues and social signals during fish communication.

Potential rivals are able to assess body size of a competitor based on the duration and intensity of the sound a yellow longnose butterflyfish produces.