Triangle Butterflyfish (Chaetodon triangulum)

The Triangle Butterflyfish is an obligate coral polyp feeder from the Indian Ocean, displaying a distinctive triangular dark marking on its pale body. Found in areas of rich Acropora coral growth, it feeds almost exclusively on coral polyps and does not readily accept substitute foods in captivity. It is virtually impossible to maintain long-term without access to live coral polyps, making it unsuitable for standard reef or FOWLR setups and collected mainly by specialists or for scientific interest.

Not suitable for standard reef aquariums — will consume Acropora and other SPS coral polyps. If kept, requires a live-coral-rich system with constant access to Acropora colonies. Some individuals can be conditioned to accept Acropora-based frozen coral preparations or Mysis enriched with coral extract, but this is rarely reliable. Long-term maintenance is extremely challenging and success is uncommon outside specialized facilities.