Rock beauty (Holacanthus tricolor) care guide

Group
Marine fish
Other names
Rock beauty angelfish, Yellow nanny, Catalineta
Family
Pomacanthidae (marine angelfishes)
Origin
Western Atlantic, Bermuda and Georgia to Rio de Janeiro through the Caribbean; rocky and coral reefs and jetties, 3–92 m
Water
saltwater
Maximum size
25 cm
Temperature
24–27°C
pH
8.1–8.4
Hardness
Salinity SG 1.020–1.025
Minimum tank
700 litres
Care level
expert
Temperament
semi_aggressive
Reef safe
no

Care

Provide a large tank with plenty of mature live rock to graze. The minimum tank size of about 700 litres is our own estimate from the adult size and habits, not a figure from the sources. No species-specific water figures are given in the sources, so the values here are general marine aquarium guidance rather than figures for this fish: 24–27 °C, pH 8.1–8.4 and a specific gravity of 1.020–1.025 (a fish-only system suits it). Keep conditions stable, with low nitrate and good oxygenation. Usually lives in long-term pairs. Can be territorial towards other angelfish. Yellow front and tail with a large black rear body. Juveniles are yellow with a blue-ringed black spot that grows into the black patch. The article gives up to 30 cm. One of the most popular Caribbean angelfish. It was only available wild-caught until captive breeding began in the 2020s. The article gives no IUCN category. Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies); Wikipedia (en.wikipedia.org/wiki/Holacanthustricolor). Checked October 2026.

Diet

Mainly sponges, plus corals, zoanthids, bryozoans, gorgonians, tunicates and algae. Wild fish can be hard to wean; offer angelfish foods containing sponge, frozen mysis, chopped seafood and marine algae several times a day.

Breeding

Marine angelfish are pelagic broadcast spawners: a pair rises into the water column, usually around dusk, and releases eggs and sperm together. A female can release 25,000–75,000 eggs in one evening; eggs hatch in 15–20 hours and larvae settle after three to four weeks. Captive breeding has been achieved commercially.

Compatibility and tank mates

Not reef safe: it grazes sponges and tunicates and will pick at stony and soft corals, clam mantles and other sessile invertebrates. Best in a fish-only system with live rock. Keep one large angelfish per tank unless the system is very large; add it after more peaceful fish and alongside robust tankmates such as tangs, larger wrasses and triggerfish of similar size. Avoid small, slow or timid fish.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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