Reticulated butterflyfish

Geographical Origin and Habitat: Chaetodon reticulatus is native to the central and western Pacific Ocean. Its distribution extends from Taiwan and the Ryukyu Islands down to French Polynesia, including the Great Barrier Reef, Micronesia, and Melanesia. It inhabits wave-exposed outer reef slopes and clear lagoons rich in Acropora corals, at depths ranging from 1 to 30 meters.

Taxonomy and Morphology: Belonging to the family Chaetodontidae, genus Chaetodon. It has a deep, rounded, and laterally compressed body. Adults reach a maximum length of about 16 centimeters. The mouth features short, specialized jaws designed to clip coral polyps with precision. The scales are shaped and positioned to emphasize the reticulated pattern.

Social Behavior: This is a monogamous species that typically lives in stable pairs. It exhibits diurnal habits and swims constantly close to coral colonies, defending its feeding territory against intruders of the same species. It is peaceful toward fish belonging to other families.

Coloration and Sexual Dimorphism: The coloration is distinctive: the body is dark, almost black, but each scale has a light yellow-cream center, creating a dense reticulated or net-like pattern. A vertical black band runs through the eye, followed by a lighter gray-blue band. The dorsal and anal fins have yellow and black margins. There is no visible sexual dimorphism.

Aquarium Setup: Requires a spacious and highly stable aquarium of at least 350-400 liters (approx. 90-100 gallons) for a pair. The layout must recreate a reef environment with mature live rock arranged to form caves and barriers, ensuring high water oxygenation and strong movement to simulate exposed reef zones.

Diet and Feeding: It is an obligate corallivore, feeding almost exclusively on Acropora polyps. In the aquarium, dietary acclimation is extremely difficult, and most specimens refuse commercial feeds. It requires a supply of live coral or the preparation of fresh food pasted onto coral skeletons to stimulate its feeding instinct.

Water Quality: Water parameters must be excellent: temperature 24-26°C (75-79°F), pH 8.1-8.4, specific gravity 1.021-1.025, and extremely low nitrates and phosphates. A powerful protein skimmer, regular 15% water changes every two weeks, and efficient biological filtration are indispensable requirements.

Compatibility and Cohabitation: Coexists peacefully with quiet reef fish such as wrasses and gobies. It is absolutely not reef-safe as it will destroy stony corals in the tank. Avoid cohabitation with aggressive species or very fast-swimming fish that could scare it and prevent it from feeding.

Aquarium Breeding: Breeding in the aquarium has never been achieved in a home environment. They are pelagic spawners that release eggs in pairs into the water column. The larvae undergo a complex planktonic stage and require specific microscopic live food, manageable only in specialized research facilities.

Risks and Diseases: The main risk is death from starvation due to food refusal in captivity. It is also highly vulnerable to external parasitic infections like marine ich. This species is recommended only for expert aquarists who have adequate resources to provide live corals.