Emperor angelfish
Pomacanthus imperator
— Where the name comes from
Pomacanthus is “gill-cover spine”, from pôma, the lid, and ákantha: at the base of the cheek it carries a stout spine used to work itself free. Imperator describes the look: parallel blue and yellow stripes over the whole body and a black mask over the eyes, adding up to full dress uniform.
— Facts
- Group
- Fish · Actinopterygii · Chondrichthyes
- Order
- Perch-likes
- Habitat
- Coral reefs with caves and ledges down to 100 metres
- Range
- The tropical Indo-Pacific and the Red Sea
- Size
- 30–40 cm, 1–2 kg
- Diet
- Sponges, tunicates, algae
- Lifespan
- 20 years
— Characteristics
- 01
The young are dark blue with concentric white rings.
- 02
The change from juvenile to adult takes two years.
- 03
It makes a dull drumming sound when disturbed.
— What sets it apart
Juvenile and adult are so unalike that they were described as two separate species and carried different scientific names for decades: the young is midnight blue with concentric white rings, the adult horizontally striped in yellow and blue. The change takes two years and happens gradually, with intermediate individuals that long confused even the knowledgeable. The likeliest explanation is that the juvenile livery signals to territorial adults that this is not a rival.
