By AFT Editorial • Last Update: October 3, 2025
The Regal Angelfish (Pygoplites diacanthus) is a stunning saltwater species known for its bold yellow, blue, and white stripes. It requires a large, stable marine tank, a carefully balanced diet, and is best kept by experienced aquarists.
This guide covers everything you need to know about Regal Angelfish, including appearance, behavior, tank setup, diet, compatibility, and reef safety. Learn how to avoid common mistakes and set up the right environment for this prized marine angelfish.
| Scientific Name | Pygoplites diacanthus |
| Family | Pomacanthidae (Marine Angelfish) |
| Origin | Indo-Pacific, Red Sea, and Great Barrier Reef |
| Adult Size | Up to 10 in (25 cm) |
| Minimum Tank Size | 125 gallons (475 liters) |
| Lifespan | 10–15 years with proper care |
| Diet | Omnivore; sponge, tunicates, meaty foods, marine algae |
| Temperament | Shy but territorial once established |
| Water Parameters | 72–82°F (22–28°C); SG 1.020–1.025; Nitrates <10 ppm |
The Regal Angelfish is instantly recognizable by its alternating vertical stripes of yellow, white, and blue. Its dorsal and anal fins are edged with striking blue margins. Juveniles look similar to adults but often show slightly duller patterns. Males and females are visually indistinguishable.
This species is shy and may hide for extended periods when first introduced. Once acclimated, it becomes more confident but can be territorial, particularly toward other angelfish. It thrives best when housed in a peaceful tank without aggressive tank mates.
A large tank of at least 125 gallons is recommended to provide ample swimming space. The tank should include live rock with caves and hiding spots. Strong water movement and stable conditions are essential. Lighting should be moderate to bright, as Regal Angelfish often graze on encrusting organisms.
Keep temperatures between 72–82°F (22–28°C) with a salinity of 1.020–1.025. Nitrate levels should be kept below 10 ppm, and phosphate as close to zero as possible. Perform 15–20% water changes every 2 weeks. Quarantine new additions before introducing them to reduce disease risk.
In the wild, Regal Angelfish feed primarily on sponges and tunicates. In captivity, offer a varied diet of frozen mysis, brine shrimp, spirulina, and angelfish-specific preparations that include sponge matter. Feed small amounts 2–3 times daily. Vitamin supplements help maintain color vibrancy and prevent deficiencies.
The Regal Angelfish is considered semi-reef safe. While some individuals ignore corals, many nip at large-polyp stony corals, zoanthids, and clam mantles. They are safer in fish-only with live rock (FOWLR) systems than full reef setups.
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Yes, they are considered challenging due to their specialized diet, need for stable water conditions, and tendency to refuse food when first introduced.
They eat sponges, tunicates, and algae in the wild. In captivity, they require sponge-based foods, mysis, and other marine preparations.
They grow up to 10 inches (25 cm) as adults.
They are semi-reef safe and may nip at corals, clams, and zoanthids. A fish-only with live rock setup is safer.
A minimum of 125 gallons (475 liters) is recommended for long-term health and swimming space.
They can live 10–15 years in captivity with proper care.
They are shy at first but can become territorial, especially toward other angelfish.
No, their striped coloration remains consistent from juvenile to adult, though juveniles may appear slightly less vivid.
Yes, live rock with caves and crevices is essential for grazing and hiding.
Feed 2–3 times daily in small portions, ensuring sponge-rich foods are included.
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