Big Longnose Butterflyfish

Geographic Origin and Biotope: Widespread in the tropical Indo-Pacific, from East Africa and the Red Sea to Hawaii, the Marquesas, and Pitcairn Islands, north to southern Japan, and south to Australia and New Caledonia. Inhabits exposed seaward reefs and drop-offs rich in coral cover at depths down to 60+ meters.

Taxonomy and Morphology: Belonging to the family Chaetodontidae. Recognized by its extremely long, needle-like snout, small mouth, and compressed yellow body. It has 10–11 dorsal spines (fewer than F. flavissimus) and rows of tiny black spots on the chest. Grows to about 22 cm.

Social Behavior: Diurnal and generally solitary, though commonly seen in stable monogamous pairs. They defend feeding territories from competitors but remain peaceful toward unrelated fish species.

Coloration and Sexual Dimorphism: Features a brilliant lemon-yellow body, with the head divided horizontally: black on top and white below. A cluster of small black spots dots the breast. A rare all-black or brown melanistic morph also occurs. No sexual dimorphism is visible.

Aquarium Setup: Needs a mature and roomy aquarium of at least 400 liters with plenty of open swimming space and live rock for foraging. A secure tight-fitting lid is essential as they are known to jump when startled.

Diet and Feeding: Specialized carnivore. Uses its long snout to pluck small crustaceans, polychaete tentacles, and echinoderm tube feet. Feed 3–4 times daily with fine frozen foods like mysis, brine shrimp, lobster eggs, and chopped clam.

Water Quality: Demands stable marine parameters and high water quality. Temperature 23–28°C, pH 8.1–8.4, salinity SG 1.020–1.025, GH 15–25, and KH 8–12. Sensitive to high nitrate levels.

Compatibility and Tankmates: Peaceful with most reef tankmates. Avoid housing with aggressive fish or hyperactive feeders that might starve it. Reef-safe with caution: it may nip at feather dusters, tubeworms, and some corals.

Aquarium Reproduction: Not bred in captivity. In nature, they are broadcast spawners that form stable, monogamous pairs.

Risks and Diseases: Starvation is the primary risk if the fish refuses food or is outcompeted. Highly prone to Cryptocaryon and external parasites if stressed or kept in suboptimal water conditions.