| Scientific name | Pterophyllum scalare (Philippine Blue line, double-recessive blue gene) |
| Common names | Philippine Blue Angelfish, PB Angel, Blue Angel |
| Adult size | 5–6 inches (12–15 cm) tall, 3–4 inches long |
| Minimum tank | 55 gallons for one pair, 75+ gallons for community |
| Water parameters | 78–82°F (25–28°C), pH 6.5–7.2, soft to moderately hard |
| Temperament | Generally peaceful, territorial when spawning |
| Care level | Beginner-friendly |
| Lifespan | 8–10 years |
The Philippine Blue Angelfish was a quiet revolution in the angelfish hobby. For most of the twentieth century, “blue” angelfish were really just silver fish photographed under cool light. Then in the late 1990s a recessive gene mutation surfaced in a Philippine breeding stock that, when expressed homozygously, produces real blue iridescence — a genuinely cool-toned, almost metallic blue across the flanks. The line spread to American breeders in the 2000s and is today one of the most affordable show-quality angelfish in the trade.
This guide covers what makes the Philippine Blue genetically different from earlier “blue” sales lines, what to expect from juveniles versus adults, and how to keep that blue intensity over years rather than watching it fade. If you are planning to buy Philippine Blue Angelfish online, the buying section at the end has notes on selecting strong specimens.
The Genetics: What Actually Makes It Blue
The Philippine Blue (PB) trait is a single recessive locus. A fish needs two copies of the PB allele to express the blue iridescence. Heterozygous (one-copy) fish look like ordinary silver scalare but carry the gene and pass it to half their offspring. This is why PB lines work like a recessive Mendelian trait: cross a homozygous PB to silver, all offspring look silver but carry one copy. Cross those carriers together and a quarter of the offspring show full blue.
The blue itself is not a true pigment. It is structural color produced by light-scattering iridophore cells in the dermis. This is why the intensity shifts with viewing angle and lighting — the same fish looks pale silver under warm light and electric blue under daylight. For genus and species background, see the Wikipedia entry on Pterophyllum and the FishBase species page.
Identification: Reading a Quality PB
Not every fish sold as “Philippine Blue” actually carries the trait or expresses it well. Markers of a quality specimen:
- Cool-toned blue across the flanks — visible under standard daylight bulbs without dramatic lighting. Sellers who only show photos under blue actinic LEDs are masking weak expression.
- Reduced black banding. True PB fish often show partial or absent vertical bars compared to wild scalare. Strong banding usually means weaker blue expression.
- Long fins, intact filaments. Same standards as any quality angelfish.
- Tall, symmetrical body. The PB gene affects color, not body shape; deformities are line-quality issues independent of the trait.
- Active, alert posture. Sluggish fish hanging in corners are stressed or freshly imported.
PB juveniles under 1.5 inches show only hints of the eventual color. By 2–2.5 inches the iridescence is locked in and you can predict adult appearance.
Tank Setup
Philippine Blue care is identical to any domestic angelfish. The PB line has the same tolerances and sensitivities as the silver wild form.
- Tank size: 55-gallon minimum (48″ long × 21″ tall) for one pair. 75+ gallons for a community of 5–6 angels with dither fish.
- Height matters. Tanks shorter than 18 inches will eventually clip dorsal fins.
- Temperature: 78–82°F.
- pH: 6.5–7.2. Most North American tap water sits in this range after dechlorination.
- Hardness: 4–12 dGH.
- Water changes: 25% weekly with temperature-matched water. Stable parameters matter more than chasing exact numbers.
Aquascape with tall plants (Amazon swords, vallisneria), vertical driftwood for spawning, and avoid sharp low decor that catches finnage.
Lighting: Maximizing the Blue
Because PB blue is structural rather than pigment-based, lighting matters more than it does for koi or marble morphs. To pull maximum visible blue:
- Use full-spectrum LEDs with strong blue (450–470 nm) and white components. Pure white “daylight” bulbs work; warm yellow bulbs flatten the effect.
- Dark substrate (black sand, dark gravel) creates contrast that makes the blue read more intensely.
- Tannin-stained water mutes the blue. PB angels look best in clear water.
- Avoid overpowering blue actinic-only lighting — it makes the fish look spectacular in photos but is unnatural for daily viewing.
Diet and Feeding
- Staple: high-quality cichlid pellet sized for the mouth (1–2 mm), 38%+ crude protein.
- Frozen rotation 2–3 times weekly: bloodworms, brine shrimp, mysis shrimp.
- Greens once weekly: blanched zucchini or spirulina flakes.
- Live foods occasionally: baby brine shrimp and live blackworms condition adults for breeding.
Feed twice daily, only what the fish clear in 60 seconds. Color-enhancing pellets containing carotenoids do not directly intensify blue (which is structural) but support overall pigment health and the subtle yellow-orange undertones that complement the blue iridescence.
Tankmates
Same rules as any domestic angelfish. Outside breeding, a PB is mostly indifferent to its tankmates. Compatible options:
- Larger schooling tetras (rummynose, lemon, congo, black skirt). Skip neons and embers.
- Corydoras catfish (sterbai, agassizii, larger species).
- Bristlenose plecos under 6 inches.
- Peaceful dwarf cichlids (Apistogramma, ram cichlids) in tanks 75 gallons and up.
- Hatchetfish, pencilfish.
Avoid tiger barbs, serpae tetras, aggressive cichlids, goldfish, and very small fish that adult angels treat as food.
Breeding
PB breeding is no different from any angelfish breeding except for the genetics. Crossing two homozygous PB fish produces 100% PB offspring. Crossing PB to silver gives 0% blue offspring but 100% carriers, useful for outcrossing to introduce vigor without losing the trait. Crossing two heterozygous carriers gives the classic 25% expressed PB outcome.
Pairs form on their own from a group of six juveniles. The female lays 200–800 eggs on a flat vertical surface; both parents fan and clean the clutch. Eggs hatch in 36–48 hours at 80°F. Wrigglers go free-swimming after another 4–5 days on baby brine shrimp and microworms.
Common Mistakes
- Buying “blue angelfish” without verifying genetics. Many sellers label silver carriers or weakly expressed fish as PB. Ask if the parents are documented homozygous PB.
- Photographing under actinic and shipping under daylight. The fish you receive may look paler than the listing photo. Honest sellers show daylight photos.
- Tank too short. Same problem as any angelfish — fins clip on shallow tanks.
- Buying solo. A single angel becomes neurotic. Buy six juveniles minimum.
- Skipping quarantine. 14-day quarantine in a bare tank prevents bringing Hexamita and gill flukes into the main display.
Where to Buy a Philippine Blue Angelfish
The PB line is widely available but quality varies. Mass-bred juveniles often express weak blue and grow into pale-flank adults. Specialist breeders maintain stabilized homozygous lines and can show you what their adults actually look like.
Amazoniafish ships Philippine Blue Angelfish direct from our Philadelphia facility on overnight FedEx Priority Overnight, UPS Next Day Air or Southwest Cargo. Every order is covered by our 100% Live Arrival Guarantee — if a fish does not arrive alive and healthy, store credit is issued without question.
The PB is the entry point to show-quality angelfish for many keepers — affordable, beautiful, and less demanding than wild-caught locality forms. For other line-bred color morphs from the same species, see also our guides to the Red Devil (Premium Koi) and Orange Marble angelfish.