Blackback Butterflyfish (Chaetodon melannotus)
Reef compatible – suitable for marine aquariums with coral and other reef inhabitants.
Care level: Intermediate
Disposition: Semi-aggressive
Minimum tank size: 50 gallons
Mature size: 7 inches
Size Information
| Size Range | Adult Size |
|---|---|
| M (2″ to 3″) | Up to 7 inches |
FAQ
Is this butterflyfish suitable for a reef tank?
Yes, the Blackback Butterflyfish is reef compatible and can coexist with coral and other reef species when properly sized and cared for.
What is the recommended tank size for this fish?
A minimum tank size of 50 gallons is required to provide adequate space and stability for this species.
How aggressive is this fish?
The Blackback Butterflyfish is semi-aggressive and may display territorial behavior, especially during feeding or when stressed.

Tim McDonald –
Added the Blackback Butterflyfish to my 50-gallon reef tank after researching compatibility. It has been active and healthy for several months. The fish is colorful and doesn’t seem to harass other tank mates, though it does defend its feeding area. Good choice for intermediate reef keepers.
Paul Mitchell –
The fish arrived healthy and has adapted well to the tank. I noticed it spends time near the back wall, possibly establishing a territory. It’s not overly aggressive, and the coral remains undisturbed. A solid addition to a balanced reef setup.
Dan Avery –
It’s a nice-looking fish, but I observed some minor nipping at smaller invertebrates. I’ve increased the tank size and added more hiding spots. Still, it’s a manageable species for intermediate hobbyists with proper tank conditions.