Red phantom tetra - Hyphessobrycon sweglesi

Scientific name: Hyphessobrycon sweglesi

Common name: Red phantom tetra

Family: Characidae

Usual size in fish tanks: 3 - 4 cm (1.18 - 1.57 inch)

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Recommended pH range: 5.7 - 7

Recommended water hardness: 4 - 12°N (71.43 - 214.29ppm)

0°C 32°F30°C 86°F

Recommended temperature range: 22 - 28 °C (71.6 - 82.4°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Middle levels

General Information

The Red Phantom Tetra (Hyphessobrycon sweglesi) is a peaceful, shimmering characin native to the upper and middle Orinoco watershed in Colombia and Venezuela, where it inhabits slow, vegetated blackwater and clearwater creeks with leaf litter and subdued light. Adults reach around 3–4 cm (1.2–1.6″) and look their best in a proper shoal of 8–10 specimens. Males develop noticeably elongated dorsal/anal fins and stronger iridescence as they mature.

Food & Feeding

Omnivorous micro-predator: use quality micro-flakes or small sinking granules as a staple and rotate fine frozen/live foods (baby brine shrimp, daphnia, cyclops, finely chopped bloodworms) several times weekly for colour and condition. Add a little vegetable matter (spirulina, blanched greens). Feed small portions 1–2× daily to preserve water quality.

Sexing

Males are slimmer with longer dorsal (and often anal) fins; females are deeper-bodied and frequently show a dark blotch with pale/white tip on the dorsal fin. Compare individuals for best accuracy.

Breeding

An egg-scattering free-spawner with no parental care. Use a separate, dim tank with very soft, acidic water, fine-leaved plants or spawning mops, and keep the tank dark since the eggs are light-sensitive. Remove adults post-spawn. Eggs typically hatch in ~24–36 hours; fry become free-swimming a few days later. Start with infusoria/green-water or vinegar eels, then switch to Artemia nauplii.

Lifespan

Commonly 3–5 years in clean, stable conditions; slightly longer is possible with excellent husbandry.

Tank Requirements & Water Parameters

Tank size: a long tank of at least 60–75 cm length for a group; larger volumes improve stability.
Water: soft, slightly acidic conditions are ideal — pH ~5.7–7.0, hardness ~4–12 °dH, temperature 22–28 °C (72–82 °F). Keep nitrate low and parameters stable.
Aquascape & light: dark substrate, wood/leaf litter, robust planting, and floating plants to diffuse light. Gentle flow, high oxygen.
Maintenance: small, frequent water changes; avoid abrupt parameter swings.

Compatibility & Tank Mates

Peaceful shoaler. Works well with other small, calm fishes that prefer soft water (small rasboras/pencils, peaceful dwarf cichlids, small Corydoras). Avoid mixing with very boisterous or fin-nipping species; keep in a proper group to minimise skittishness.

Behaviour & Usual Place in the Tank

Active mid-water schooler that moves between open lanes and cover. Provide both open swimming space and shaded retreats for confidence and display.

Short Description

Red Phantom Tetras are sparkling Orinoco characins that thrive in soft, slightly acidic, dimly lit aquaria. Keep them in groups, feed varied micro-foods, and breed them in very soft, darkened setups—eggs hatch in about a day. Most stock in the trade is captive-bred, with wild fish uncommon.

Q&A

Where are they from? The upper and middle Orinoco basin (Colombia & Venezuela).
How many should I keep? At least 8–10 to see natural schooling and displays.
Are the eggs light-sensitive? Yes — keep the breeding tank dark to improve hatch rates.