TankBud

Flagfin angelfish

Apolemichthys trimaculatus

Also known as Threespot Angelfish, Three-spot Angelfish

SaltwaterFish

Flagfin angelfish (Apolemichthys trimaculatus)
Diego Delso · CC BY-SA 4.0

Care at a glance

Temperature
73–81°F
23–27°C
pH
8.1–8.4
Adult size
10.2 in
26 cm
Minimum tank
100 gal
380 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Middle
Diet
Omnivore
Difficulty
Difficult
Breeding
Hard
Rarity
Common
Reef safe
Reef safe with caution
Family
Pomacanthidae
Origin
Indo-Pacific, from East Africa to Samoa, north to southern Japan and south to Australia

Overview

The flagfin angelfish is a yellow angel for a mature, well-established saltwater tank. It is a hard fish to keep, best in experienced hands.

Did you know

The first captive-bred flagfin angelfish came from a Bali-based hatchery. That was notable, because wild adults are among the pickiest eaters in the family. A wild fish can waste away in a new tank if it never learns to accept prepared food.

Caring for the flagfin angelfish

Give a flagfin angelfish a well-established tank of at least 100 gal (380 L), with a strong algae film and good water movement. It arrives shy and needs a head start of food already growing on the rock. It is not a fish for a young, understocked tank.

Keep the water at 73 to 81°F (23 to 27°C) with a pH of 8.1 to 8.4. This species leans on sponge in its natural diet more than most. Feed a sponge-based angelfish preparation along with spirulina and marine algae several times a day.

Flagfins are mostly peaceful once settled, though shy and slow to come out at first. They grow bolder over time and occasionally spar with similarly shaped fish. They do not tolerate other angelfish.

A hungry flagfin will pick at soft and stony corals and clam mantles, so it is reef safe only with caution. It does best in a fish-only or FOWLR setup. Breeding it is hard.

Good to know

The flagfin angelfish has a bright yellow body with blue-edged scales and blue lips. Dark spots near the eyes and forehead give the species its threespot and flagfin names. How many spots show up varies between individual fish and populations. It belongs to the family Pomacanthidae.

In the wild

Flagfin angelfish live on lagoon and seaward reefs across the Indo-Pacific, from East Africa to Samoa, north to southern Japan and south to Australia. They usually stay near coral growth, from about 3 to 60 meters. Juveniles are secretive and stay below 25 meters, while adults form small, loose groups at moderate depth.

Common questions

What size tank does a flagfin angelfish need?

A flagfin angelfish needs at least 100 gal (380 L). It spends most of its time in the middle.

What temperature and pH does a flagfin angelfish need?

A flagfin angelfish is comfortable at 73–81°F (23–27°C) with a pH of 8.1–8.4.

What does a flagfin angelfish eat?

A flagfin angelfish leans on sponge in its natural diet more than most. Feed it a sponge-based angelfish preparation, with spirulina and marine algae, several times a day.

How big does a flagfin angelfish get?

An adult flagfin angelfish reaches about 10.2 in (26 cm).

Related species