Yellow Longnose Butterfly - Forcipiger flavissimus

Both species are sold as Longnose Butterflyfish, but they differ in a few ways. F. flavissimus (often called the Yellow Longnose) is more commonly imported, hardier overall, and usually adjusts better to captive diets. F. longirostris (True Longnose) has a noticeably longer, thinner snout and more delicate body lines; it tends to be shyer, more prone to stress, and often more selective with food. For most home aquariums, F. flavissimus is usually the better choice due to its better track record of adapting to prepared foods and handling typical captive conditions. If you want F. longirostris, provide an especially calm, mature system with abundant live rock, and be prepared for a more demanding acclimation and feeding process.

Start with a mature tank rich in natural food: live rock with pods, feather dusters, and tiny worms will support it during the initial acclimation. Right away, offer frozen mysis shrimp, enriched brine shrimp, finely chopped clam or mussel, and small pieces of shrimp, broadcast-fed multiple times per day near where it is exploring. Use feeding clips with sheets of clam on the half-shell or mashed seafood rubber-banded to rock to trigger natural picking behavior. Many individuals respond well to live blackworms or live enriched brine at first; once it is eating those, gradually mix in frozen options until it takes them readily. Avoid strong competition from fast eaters; feed those on the opposite side of the tank. Patience is key—consistent, frequent small feedings and minimizing stress usually turn them into strong, prepared-food eaters.

Early signs include frequent hovering and “probing” with its snout over a specific coral colony, followed by tiny pecks and intermittent polyp retraction in only that area. Over time, affected corals will show poor extension when the lights are on, localized tissue thinning, and slower growth, even while other corals look normal. Longnose Butterflyfish often ignore many SPS species but may pick at fleshy LPS (e.g., Trachyphyllia, Lobophyllia, open brains, some Favias), Zoanthids, and occasionally large-polyp soft corals like mushrooms and some leathers. Euphyllia (torches, hammers, frogspawns) may or may not be targeted; individuals vary a lot. If you see repeated attention to a coral followed by chronic polyp retraction, assume it’s being sampled and be ready to separate fish or coral before long-term damage occurs.

Aim for a tank at least 4 feet long (75–90 gallons minimum for a single specimen), with emphasis on horizontal swimming space and numerous caves and arches. Use an open, “reef wall plus islands” layout: a primary rock structure along the back with overhangs and crevices, and a few smaller rock islands toward the front. This lets the fish weave in and out of rockwork—mimicking how it hunts for invertebrates on reefs—while still having open lanes for cruising. Keep tall rockwork slightly away from the glass so it can swim behind it; this escape route dramatically improves its sense of security. Provide moderate to strong, but not turbulent, flow, with some lower-flow pockets within and around the rock so it can forage comfortably.

Problem tankmates often include territorial dwarf and large angelfish, aggressive tangs (especially Acanthurus and some Zebrasoma), and pugnacious wrasses or dottybacks that dislike new, similarly sized fish. They may chase the Longnose away from key feeding areas or repeatedly lunge at it, especially during the first week. To reduce aggression, feed more frequently and in multiple spots so the bully doesn’t control all food. Rearrange some rockwork just before adding the Longnose (or temporarily move a known aggressor to a sump or acclimation box), which disrupts established territories. An acclimation box inside the display helps existing fish get used to the newcomer visually without physical contact; after a few days to a week, release the Longnose at lights-out. Avoid combining it with highly aggressive species in smaller tanks; in marginal cases, removing the most aggressive fish permanently is the only lasting solution.