Copperband Butterflyfish

Geographic Origin and Biotope: Western Indo-Pacific Ocean: from the Persian Gulf to Japan, down to the Australian Great Barrier Reef. Inhabits coastal coral reefs rich in crevices, sheltered turbid bays, and estuaries. Prefers to explore vertical walls meticulously searching for holes and cracks (1-25 meters in depth).

Taxonomy and Morphology: Known as the Copperband Butterflyfish. Iconic laterally flattened disc morphology topped by a strictly tubular and elongated snout, specialized for inspecting crevices unreachable by other fish. The dorsal fin carries sharp spines. Grows up to 20 cm (8 inches).

Social Behavior: Peaceful, very delicate, and of formidable elegance. Swims gracefully hovering along the rockwork, with continuous interruptions to peer into holes. It has a very nervous disposition if surrounded by large or frantic fish, tending to stop feeding and hide if intimidated.

Coloration and Sexual Dimorphism: Magnificent bright silvery white body, crossed by four distinct copper-orange vertical bars finely edged in dark brown. The posterior dorsal fin sports a large prominent black eyespot, a ploy to deceive predators about the position of the head. No evident sexual dimorphism.

Aquarium Setup: Minimum 400 liters (105 gallons). Absolute requirement: tons of mature Live Rock of excellent quality, which will provide the microscopic annelids necessary for its survival in the first dramatic months of acclimation. A quiet environment without turbulent tankmates (no Zebrasoma or large Triggerfish).

Diet and Feeding: The hardest challenge: it is an obligate micropredator (eats small tube worms, crustaceans, and Aiptasia). In the store, NEVER buy specimens that do not eat. It often wastes away rapidly refusing any substitute. Force feeding with live mysis, bloodworms, or by smearing fresh clams/mussels into open shells placed in the rockwork.

Water Quality: Fragile as crystal to water variations. Absolutely pure water: specific gravity 1.023-1.025, pH constantly 8.2-8.4, Temperature 24-28 °C (75-82 °F). A measurable level of ammonia or nitrites is lethal in a few hours. Frequent but small water changes to avoid stressing the animal.

Compatibility and Tankmates: Considered one of the few "Reef Safe with caution" Butterflyfish. It will exterminate all Aiptasia, ornamental tube worms (Feather Dusters), and often small Tridacna clams, but generally does not touch corals (SPS and LPS). Never keep together with its cousin Forcipiger flavissimus or other Chelmon: they will fight to the death.

Aquarium Reproduction: Totally precluded in captivity. They form stable monogamous pairs that defend territories on the ocean reef. They produce pelagic eggs that rise to the surface, and the subsequent Tholichthys larva wanders for weeks before settling. All commercial specimens are wild-caught (request the "cyanide-free" guarantee).

Risks and Diseases: The mortality rate from starvation in the first month is tragically high (over 50%). If stressed, it invariably contracts Lymphocystis or gill flukes. Pharmaceutical treatments containing Copper are often fatal to it. Only buy plump specimens that attack frozen mysis.