---
title: Blackback Butterflyfish (Chaetodon melannotus)
scientific_name: Chaetodon melannotus
common_name: Blackback Butterflyfish
taxon: Butterflyfishes
conservation_status: LC - Least Concern
published: 2024-10-28T00:46:10.872Z
updated: 2026-08-29T00:30:26.262Z
tags: Blackback Butterflyfish, Chaetodon melannotus, Butterflyfishes, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/butterflyfishes/blackback-butterflyfish
---

# Blackback Butterflyfish (*Chaetodon melannotus*)

## Quick facts

- **Group:** Butterflyfishes (*Chaetodontidae*)
- **Size:** up to 18 cm
- **Depth:** 2-20 m
- **Max age:** 20 yrs
- **Diet:** Corallivore
- **Activity:** Diurnal
- **Rarity:** Uncommon
- **Habitat:** soft coral patches and staghorn thickets
- **Reproduction:** Broadcast spawner, Gonochoric
- **Conservation status:** LC - Least Concern

## How to recognise it

- white body with fine dark diagonal lines
- black saddle across the base of the tail
- yellow snout, dorsal and anal fins
- back turns black with two white patches at night or when alarmed
- up to 18 cm

Find this fish asleep at night and it is wearing different clothes. The back that was white by day has gone black, broken only by two white patches, and the change also comes on in daylight if the fish is badly frightened. Divers who have photographed the same individual an hour apart have come back with what looks like two species.

By day it is white with fine dark diagonal lines, a yellow snout and yellow dorsal and anal fins, a black bar through the eye and a black saddle across the base of the tail. The saddle is the mark to look for, and it holds up in a poor photograph.

What it eats was worked out on the reef flat at Sharm El-Sheikh, and the answer is unusual. Nearly all of its bites, over ninety five percent, went into soft corals rather than stony ones, mostly Sinularia and Litophyton, with a clear preference for the pulsing Heteroxenia and a clear refusal of Sarcophyton and Lobophytum despite both being right there. It fed at about forty bites every five minutes and held a territory averaging roughly five hundred square meters.

Soft corals are chemically defended, which is why most fish leave them alone, and this one has evidently solved that problem. It also means the fish is not chained to the same food as the strict stony-coral feeders on the same reef. When a bleaching event kills the Acropora and those species disappear, this one has something left to eat. Soft corals are not immune to heat either, so this is an advantage rather than a rescue.

Adults are usually alone or in a pair, in the top 20 m, over patches of soft coral and among staghorn thickets. Juveniles stay inshore.

## Also known as

- **English:** blackback butterflyfish, Black-back Butterflyfish, Black-backed Coralfish
- **French:** Chétodon à dos noir, Papillon à dos noir, Pavillon à dos noir
- **Polish:** Ustnik ciemnopregi
- **Japanese:** アケボノチョウチョウウオ, Akebono-chôchô-uo, Akebonochochouo
- **Chinese:** 太陽蝶, 曙色蝶, 黑背蝴蝶魚
- **DA:** Sortrygget fanefisk
- **VI:** Cá Bướm hai chấm

## Scientific synonyms

- *Chaetodon abhortani* Cuvier, 1831
- *Chaetodon dorsalis* Rüppell, 1829
- *Chaetodon marginatus* Cuvier, 1831
- *Chaetodon melanotus* Cuvier, 1831
- *Chaetodon reinwardti* Günther, 1860
- *Chaetodon reinwardtii* Günther, 1860
- *Mesochaetodon strongylochaetodon melannotus* (Bloch & Schneider, 1801)
- *Tetragonoptrus dorsalis* (Rüppell, 1829)
- *Tetragonoptrus melanotus* (Bloch & Schneider, 1801)

## Range

East Africa, Indian Ocean, Kenya, Madagascar, Mozambique, Red Sea, Republic of Mauritius, Seychelles, South Africa

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/butterflyfishes/blackback-butterflyfish)*
*Updated: August 29, 2026*