Butterflyfish
Longfin Bannerfish
Heniochus acuminatus
The Longfin Bannerfish trails a long white dorsal filament like the true Moorish Idol it's often mistaken for — but it's a butterflyfish, not a Zanclid, and far easier to feed. It's the pickier of the two Heniochus 'bannerfish': hobby and retailer sources both flag it as a threat to corals and sessile invertebrates, so keep it in a fish-only or very cautious reef, and add just one per tank.
Keep just one per tank — two will fight.
Something look wrong? Report an errorTankmates
How Longfin Bannerfish gets on with the rest of the reef, checked pair by pair by the same engine as the live pre-flight.
Best kept apart
A real clash — aggression, predation or a same-genus fight.
Good tankmates
No conflicts — a few popular ones to start with.
