Marine life  /  Butterflyfish  /  Schooling bannerfish
Reviewed 2026-09-06
Species entry

Schooling bannerfish

Heniochus diphreutes

The bannerfish that occurs in dozens rather than pairs, and it is a facultative cleaner.

Size
To 21 cm
Depth
5–45 m
Habitat
Open water over slopes and drop-offs
Active
Daylight
Range
Indo-Pacific
Rarity
Bali
2 stars of 5, usually seen in a week
SP-01
schooling bannerfish · full body · habitat
4:3 · min 2400px

To about 21 cm, white with two broad black bars, a yellow dorsal and tail and a long white dorsal filament — very close to the longfin bannerfish. The differences are a shorter and blunter snout, a slightly shorter filament, a black area on the chest that reaches the pelvic fin base, and, practically, the behaviour: this species forms mid-water aggregations of tens to hundreds while the longfin bannerfish is in pairs on the reef.

It feeds on zooplankton in the water column over slopes and drop-offs. Juveniles and some adults clean parasites from larger fish, and a school over a cleaning area will work over passing surgeonfish and jacks. It is a species of current-exposed reef and is far less numerous on sheltered muck slopes. Recorded from about 5 to 45 m.

Where to find:

LocationRarity Best monthsDepthHabitat
Bali Indonesia editorial estimate
2 stars of 5, usually seen in a week
Year-round
5–45 m
Open water over slopes and drop-offs
Papua New Guinea Papua New Guinea editorial estimate
2 stars of 5, usually seen in a week
Year-round
5–45 m
Drop-offs and reef slopes
Anilao Philippines editorial estimate
3 stars of 5, a good week should turn one up
Year-round
5–40 m
Open water over reef slopes
Lembeh Strait Indonesia editorial estimate
4 stars of 5, two or three a season
Year-round
5–40 m
Reef slopes and drop-offs

Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.

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