Blackback Butterflyfish - Chaetodon melannotus

Blackback Butterflyfish (Chaetodon melannotus)

The Blackback Butterflyfish is an attractive and active marine butterflyfish recognised for its pale body, fine dark diagonal lines and distinctive dark rear section across the upper body. Its elegant shape and contrasting markings make it an eye-catching addition to spacious marine aquariums. Although generally peaceful towards unrelated fish, its natural feeding behaviour includes coral polyps and other reef organisms, so it is not considered suitable for delicate reef displays.

Common Name:
Blackback Butterflyfish, Black-backed Butterflyfish

Scientific Name (Latin):
Chaetodon melannotus

Maximum Size:
Approximately 18 cm

Water Type:
Marine

Origin / Natural Habitat:
The Blackback Butterflyfish has a broad Indo-Pacific distribution and is associated with coral-rich lagoons, reef flats and seaward reef slopes.

It typically remains close to coral and rocky structure, where it spends much of its time searching reef surfaces for food.

Water Parameters:
Temperature: 24–26°C
pH Range: 8.1–8.4
Salinity: SG 1.024–1.026
Nitrate: Low and stable
Ammonia/Nitrite: 0 ppm

Temperament:
Peaceful to Semi-Aggressive

The Blackback Butterflyfish is generally peaceful towards unrelated marine fish but may become territorial towards other butterflyfish, particularly similarly patterned species.

Adults may occur in pairs, although keeping a single specimen is often the simplest option in a home aquarium unless a compatible established pair is available.

Diet:
Omnivore / Corallivore

The Blackback Butterflyfish naturally feeds on coral polyps and a range of small reef-associated foods.

In the aquarium, offer a varied diet including frozen mysis, enriched brine shrimp, finely chopped prawn, mussel, specialist butterflyfish foods and quality marine pellets.

Several smaller meals throughout the day are preferable, particularly while the fish is settling into a new aquarium.

Minimum Tank Size:
Approximately 300 litres

Its adult size and active swimming behaviour mean the Blackback Butterflyfish benefits from substantial horizontal swimming space alongside established rockwork and shelter.

Behaviour & Activity:
The Blackback Butterflyfish is an active daytime swimmer that spends much of its time exploring reef structure and searching coral and rock surfaces for food.

Provide plenty of open swimming room together with caves, overhangs and secure rockwork.

It should be kept with suitably calm tankmates that will not continually intimidate or outcompete it at feeding time.

Reef Safe:
Not Reef Safe

The Blackback Butterflyfish should not be considered reliably reef safe.

Coral polyps form an important part of its natural diet, so hard corals and potentially other sessile reef invertebrates may be picked at or consumed.

It is therefore better suited to fish-only marine aquariums or systems where coral damage is an accepted risk.

Special Requirements or Care Notes:
Provide a mature marine aquarium with plenty of open swimming space, established rockwork and sheltered areas.

Newly introduced specimens should be monitored carefully to ensure they begin feeding consistently.

Offering a wide variety of frozen and prepared foods can help establish a strong feeding response and maintain healthy body condition.

Avoid highly aggressive tankmates that may prevent the butterflyfish from feeding comfortably.

Stable water quality, good oxygenation and strong filtration are important for long-term health.

Because this species naturally feeds on coral polyps, it should not be selected for a valuable mixed reef aquarium where coral safety is a priority.

Suitable for:
Intermediate

Availability:
Availability can vary depending on season, collection area and supplier.

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.