Species name: Apolemichthys trimaculatus

Common names: Flagfin or Threespot angelfish

Family: Pomacanthidae (Angelfishes)

Order: Perciformes (perch-likes)

Class: Actinopterygii (ray-finned fishes)

Maximum length: 10.2 in. (much smaller length in captivity.)

Minimum tank size: 100 gallon

Hardiness: Difficult due to its dietary requirement and its poor ability to adapt to other foods.

Aggressiveness: Peaceful but may fight with close relatives. Keep only with other peaceful fishes and do with angels.

Reef Compatibility: No. Prone to nip at sessile invertebrates (soft and stony corals) and clam mantles.

Distribution: Indo-West Pacific: East Africa south, north to southern Japan, south to Australia.

Diet: Omnivore. Feeds mainly on sponges, tunicates and algae. In captivity, feed with mixed fare of sponge-containing frozen angelfish rations, Spirulina, vitamin-enriched brine shrimp, mysid shrimp, plant material, and live rock for grazing and hiding. Feed at least 3 times a day. It is one of the more difficult angelfish to adapt to prepared foods. Juveniles are the easiest to adapt.

Additional information:


In the wild, the Flagfin angelfish is from the Indo-West Pacific region where it inhabits lagoons and seaward reefs at depth of 10 to 130 feet. It is usually seen in pairs or as solitary individuals.

Its strongly compressed body is bright yellow. It have blue lips, a black spot on the forehead and a dark spot behind the gill cover. Juveniles have thin black line through eye, a series of golden bars on the side and lack the spots around the head. The black patch on the caudal fin of the young disappears in adults.

Beautiful Angel, the Flagfin Angel is definitely one of the Aquarists favorites. It is a difficult fish to keep but not as difficult than the Red Sea Regal Angel. It usually fares poorly in the home aquarium but chances of success are increased in a system with plenty of invertebrate encrusted live rock.

The ideal aquarium should have a water temperature of 72 – 78 F, a pH between 8.1 – 8.4 and a specific gravity of 1.020 – 1.025. Should be housed in a well established reef system with plenty of live rock to graze on, several hiding places and room to swim. Will have a tough time to addapt in a bare tank with no live rock.