Foureye butterflyfish

This species is native to the warm waters of the Western Atlantic Ocean, ranging from the coast of North Carolina (USA) and Bermuda down to southern Brazil, including the Gulf of Mexico and the entire Caribbean Sea. It commonly inhabits shallow coral reefs, seagrass beds, and rocky areas at depths ranging from 2 to 20 meters, frequently found in habitats rich in gorgonians and stony corals.

Belonging to the family Chaetodontidae, Chaetodon capistratus features a disk-shaped, laterally compressed body with a pointed snout and a small terminal mouth containing brush-like teeth. Adults can grow to a maximum total length of approximately 15 centimeters. Its body shape is highly adapted for executing quick maneuvers within complex reef structures.

It is a diurnal and highly active swimmer. Foureye butterflyfish are known for forming long-term, stable monogamous pairs that forage together and defend a feeding territory. Juveniles are solitary and show territorial behavior in shallow micro-habitats such as tide pools or seagrass beds to avoid predators.

The body is light gray to silvery-white with dark lines forming a chevron pattern on the flanks. Its most distinctive feature is a large black eyespot ringed in white near the tail, which mimics a real eye to confuse predators, while the actual eye is camouflaged by a dark vertical band. There is no visible external sexual dimorphism.

Requires a mature marine aquarium of at least 350 liters. The setup must include plenty of live rock arranged to create caves, swim-throughs, and shaded areas for shelter, while leaving a large open space for active swimming. Efficient protein skimming and moderate water flow are essential to replicate its natural environment.

An omnivore feeding on coral polyps, polychaete worms, tunicates, and small crustaceans. In captivity, it can be a picky feeder initially. Offer a varied diet of high-quality frozen foods like mysis shrimp, brine shrimp, and chopped clams, along with marine algae and spirulina-rich preparations. Over time, it may accept high-quality pellets.

Demands clean and stable marine water parameters: temperature between 24°C and 26°C, pH range from 8.1 to 8.4, specific gravity (SG) between 1.020 to 1.025, and carbonate hardness (KH) of 8 to 12 dKH. Keep ammonia and nitrite at zero, and maintain nitrate levels below 15 ppm with regular water changes.

Not considered reef safe, as it will nip at stony corals, zoanthids, and soft corals. It is highly compatible with other peaceful marine species such as wrasses, tangs, clownfish, and dartfish. Do not house with aggressive or fast-feeding tankmates that might outcompete it for food or stress it.

Breeding in the home aquarium has not been achieved. They are pelagic broadcast spawners, releasing gametes into open water where eggs float and drift with currents. Rearing the delicate planktonic larvae requires specific, microscopic live prey that is extremely difficult to culture in closed home systems.

Susceptible to common marine ectoparasites like Cryptocaryon irritans (marine ich) and Oodinium (velvet). Stress from transport, poor water quality, or inappropriate tankmates can easily trigger infections. A quarantine protocol is highly recommended before introducing this species to the main display tank.