Keyhole angelfish

Geographic Origin and Biotope: Indo-Pacific: from Christmas Island and Queensland (Australia) to Taiwan and Vanuatu. Inhabits shallow lagoons and sheltered reefs.

Taxonomy and Morphology: Member of the Pomacanthidae family. The largest of the Centropyge genus, growing up to 19 cm (7.5 inches) in length.

Social Behavior: Bold and active. Establishes large territories and can be quite aggressive towards other dwarf angelfishes or food competitors.

Coloration and Sexual Dimorphism: Jet-black body with a distinctive white vertical keyhole-shaped patch on the flank. The anal fin has a bright yellow margin. Males are larger.

Aquarium Setup: Minimum aquarium size of 200 liters (55 gallons). Provide plenty of rocky caves and passageways to accommodate its larger size.

Diet and Feeding: Omnivorous. Grazes on filamentous algae. Offer dried nori, spirulina pellets, and frozen mysis or brine shrimp daily.

Water Quality: Keep standard marine parameters stable: temperature 24-28°C (75-82°F), pH 8.1-8.4, specific gravity 1.020-1.025, and KH 8-12.

Compatibility and Tankmates: Less reef safe than smaller dwarf angels; has a high tendency to nip at LPS corals and clam mantles. Best kept as the sole angelfish.

Aquarium Reproduction: Unrecorded in domestic systems due to broadcast spawning habits and difficult pelagic larval stages.

Risks and Diseases: Highly resilient, but can contract marine ich or bacterial infections under poor water quality or crowding.