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Masked Angelfish

Genicanthus personatus

An exceptionally rare, endemic Hawaiian treasure inhabiting extreme ocean depths. Distinctive for its bright mask, this pristine white angelfish demands massive, mature systems and impeccable water quality.

Taxonomy

Class:Actinopteri

Order:Perciformes

Family:Pomacanthidae

Genus:Genicanthus

Species:Genicanthus personatus

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Water Temperature

19 - 23 °C

pH Value

8.1 - 8.4

Water type

Marine

Tank level

All levels

Adult size

21 cm

Minimum tank volume

>= 800 L

Minimum group

>= 1

8 - 12 dKH

Species description

Geographical Origin and Habitat: Endemic to the Northwestern Hawaiian Islands and Midway Atoll. It inhabits very deep outer reef slopes and drop-offs exposed to strong ocean currents, typically at depths between 20 and over 170 meters, where water temperatures are significantly cooler than in shallow tropical lagoons.

Taxonomy and Morphology: Belongs to the family Pomacanthidae, genus Genicanthus. It features a laterally compressed body with a lyre-shaped caudal fin (lyretail) characteristic of this genus of planktivorous angelfish. Reaches a maximum standard length of about 21 centimeters as an adult.

Social Behavior: Peaceful and active species, an open-water swimmer that lives in groups or small harems consisting of a single male and several females. Unlike many other angelfish, it spends most of its time in the water column hunting for planktonic food, showing little interest in the substrate.

Coloration and Sexual Dimorphism: Sexual dimorphism is extremely pronounced. Females have a pure pearly-white body with a black mask covering the eyes and mouth, and wide black margins on the caudal fin. Adult males have a bright white body with a striking orange or golden mask on the face and yellow-orange margins on the pectoral, dorsal, and anal fins.

Care, breeding and tankmates

Aquarium Setup: Requires a very large and mature marine aquarium of at least 500 liters, with ample open space for swimming and rockwork arranged to form overhangs and caves for shelter. It is important that the rock structures are highly stable to prevent any collapse.

Diet and Feeding: Primarily a planktivorous species. In the wild, it feeds on zooplankton, copepods, and small suspended crustaceans. In the aquarium, it must be fed multiple times a day with high-quality frozen foods such as mysis, brine shrimp, lobster eggs, copepods, and vitamin-enriched pellet foods.

Water Quality: Being a deep-water species, it requires cool temperatures, ideally between 18 and 23 °C (64-73 °F). Maintain pH between 8.1 and 8.4, and specific gravity at 1.022-1.025. The use of a water chiller and a powerful filtration system with an oversized protein skimmer is indispensable.

Compatibility and Cohabitation: Highly peaceful and completely reef-safe, as it does not nip at stony corals, soft corals, or clams. It can coexist with other peaceful reef fish. Avoid housing it with highly aggressive or fast-swimming fish that could intimidate it or outcompete it for food.

Aquarium Breeding: Protogynous hermaphrodite. Dominant females can transition into males. Breeding in home aquariums is extremely difficult, but has been achieved successfully by a few specialized breeders and marine research institutions.

Risks and Diseases: Exceptionally rare and expensive species. The main risks include decompression sickness if wild-caught, sensitivity to temperatures above 24 °C (75 °F), and susceptibility to skin parasites. Requires expert care, very careful acclimation in dim light, and constant monitoring of parameters.

Geographic Origin and Distribution

Endemic to the Northwestern Hawaiian Islands and Midway Atoll. It inhabits very deep outer reef slopes and drop-offs exposed to strong ocean currents, typically at depths between 20 and over 170 meters, where water temperatures are significantly cooler than in shallow tropical lagoons.

Origin

Tropical oceans and reefs

Fish profile

Temperament: Peaceful
Diet: Omnivore
Sex ratio: Harem
Feeding frequency: THREE_FOUR_DAILY
Bioload: The bioload is moderate. Efficient biological filtration is required. Regular water changes keep nitrates low.
Flow: Strong
Jump risk: Yes
Reproduction: Oviparous
Compatibility & tankmates: Reef safe
Tank level: All levels

FishBase

Window to the official scientific data of the species

Data synced on: 06/15/2026

Scientific Parameters & Models

Trophic level: 2.7 ± 0.31 se
Resilience: Medium (1.4 - 4.4 years)
Phylogenetic uniqueness (PD50): 0.501
Bayesian Length-Weight: a = 0.0302, b = 2.89

Image gallery

Licensed images linked to the species or, when marked, to the closest representative taxon.

Related species

Recommendations grouped by close relatives, companion choices, and similar care.

Variants and close relatives

Same atlas type, nearby scientific identity, genus, or family.

Japanese swallowtail angelfish

Genicanthus semifasciatus

Species description

Care, breeding and tankmates

Geographic Origin and Distribution

Origin

Fish profile

Scientific Parameters & Models

Image gallery

Related species

Variants and close relatives

Japanese swallowtail angelfish

Blackspot Angelfish

Lamarck's angelfish

Ornate Angelfish

Watanabe's Angelfish

Zebra angelfish

Bandit Angelfish

Conspicuous Angelfish

Peppermint Angelfish

Narc Angelfish

Bluestriped Angelfish

Japanese Pygmy Angelfish

Blackear Angelfish

Abe's Angelfish

Colin's Angelfish

Debelius' angelfish

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Boschma's hermit crab

Cook's hermit crab

Danai's hermit crab

De Man's Hermit Crab

Feather Duster Worm

Lysmata prima shrimp

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