That does not explain why? I thought since you said that, you would have something other than fish sales sites. I have been looking for the information and have found nothing in any write ups on the fish that state they cannot be kept in a reef tank. The thingsI found out about these fish as far as eating habits go, is, they eat zooplankton (maybe a reason, but so do other reef safe fish), and benthic invertebrates.
Here is one of the references.
Heniochus acuminatus (Linnaeus)
(Long-finned Bannerfish; Ababang)
SL: to 20 cm (photo: 7 cm SL, Agana, 3 m)
This species is moderately common in deep, protected harbors, lagoons, and channels from 2 to over 32 m. Along outer reef slopes, it occurs in somewhat deeper water, generally from below 20 to at least 75 m. It feeds on zooplankton and occurs in pairs or in small groups.
and another:
A plantivorous species that generally remains within a few meters of the reef. Juveniles may sometimes pick on parasites on the epidermis of other fish.
plantivorous
n. plant-eating.
more:
Usually living along reef front, in pairs or solitare, seldom in groups. Feeds on plankton, more rarely on benthic invertebrates. Juveniles can act as cleaners, feeding on parasites collected on other fish skin.
Benthic: organism living on or in close proximity with the sea bottom. The bottom organisms system is called benthos.
The benthos live on the ocean floor. Starfish, oysters, clams, sea cucumbers, brittlestars, and anemone are all benthos. Most benthos feed on food as it floats by or scavenge for food on the ocean floor.
So far, I have found no reference to eating or harming corals of any type. ????
Again. I would like to get validity or from anyone, experience that vears in the direction that this thread has taken to banner fish being not reef compatible..