Common Names: Yellow longnose butterflyfish, longnose butterfly, forcepsfish, lauwiliwilinukunuku`oi`oi (Hawai`i)
Type Locality: Clarion and Revilla Gigedo Islands, off western coast of Mexico
Range: has the widest distribution among butterflies, from the west coast of North and Central America to the east coast of Africa
Taxonomic Troubles: None, this is the original name
Size: 22 cm (8 to 9 inches) TL.
Preferred Water Chemistry: Tropical marine, often kept at salinities down to 1.020 to increase oxygenation and inhibit Cryptocaryon, to which the fish is especially susceptible.
Difficulty: Generally hardy, careful quarantine is needed because of its susceptibility to parasitic infection, but when well cared for, it is a tough fish. This is one of the “good” butterflies.
Tank Setup: Not to be considered reef safe, as these fish naturally graze on invertebrates. Peaceful except with its own kind, it needs tankmates that will not harass it. A FOWLR setup is perfect.
Feeding: Primarily a carnivore. Will eat most meaty foods.
Breeding: Not reported in the aquarium. It has a rather prolonged planktonic larval phase.
Typical tall, laterally compressed butterflyfish body, plus a long, pointed snout. Top half of head black, with bottom and snout white; rest of body and fins bright yellow, a dark spot on the anal fin.
Many butterflyfish are horrible choices for a home aquarium. This one, however, is a very good choice for fish-only systems of sufficient size. In addition, this species is perfect as a first butterfly for the novice marine hobbyist, as is its very similar but even longer-nosed congener, F. longirostris, which shares most of its common names with F. flavissimus—except for “long longnose butterfly,” which is given to distinguish it from the other longnose butterfly.
Although these fish do not usually feed on coral polyps, they may, and they will definitely eat tubeworms and other ornamental invertebrates. Whether in the wild or in captivity, they spend their days flitting over the reef or live rock, picking here and there, always looking for a morsel of meat.