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FishbeginnerFreshwater

Black Phantom Tetra

Megalamphodus megalopterus

AnimaliaChordataActinopterygiiCharaciformesCharacidae

📍 Rio São Francisco & upper Río Paraguay, Brazil

Ask Finn

Stunning tetra with a smoky black body and large, fan-like dorsal fin on males. Females develop reddish hues. Males display to each other with fins erect — a mesmerising show in a planted tank.

Size1.75"
Min Tank15g
School6+
peaceful
Zonemid

Care Guide

Diet

Black Phantom Tetras are omnivores that thrive on a varied diet of high-quality flake foods, micro pellets, and small frozen foods like brine shrimp and daphnia. Feed small amounts once daily, offering only what they can consume in 2-3 minutes. Occasional vegetable matter such as blanched spinach supports digestive health.

Behavior

These tetras are peaceful schooling fish that display fascinating fin-flaring behavior, especially among males in planted environments. They are mid-water swimmers that remain active throughout the day and show increased confidence and color intensity when kept in groups of 6 or more. They are generally non-aggressive toward other peaceful species but may nip at very slow-moving fish.

Breeding

Breeding Black Phantom Tetras in captivity is moderately difficult and requires soft, acidic water (pH 5.5-6.5) with dense vegetation or spawning mops. Condition breeding pairs with live foods for 1-2 weeks, then transfer to a separate breeding tank; parents will eat eggs and fry if not removed. Fry are tiny and require infusoria or liquid fry food for the first week before accepting micro foods.

Common Diseases

Ich (White Spot Disease)

Symptoms

White spots on body and fins, rapid breathing, lethargy, rubbing against objects

Treatment

Raise temperature gradually to 28-30°C, perform daily 25% water changes, use aquarium salt (1 tsp per 5 gallons) or commercial ich treatment for 7-10 days

Fin Rot

Symptoms

Frayed or deteriorating fin edges, discoloration at fin bases, lethargy

Treatment

Improve water quality with frequent partial water changes, remove any sharp tank décor, treat with antibacterial medication if severe

Neon Tetra Disease

Symptoms

Loss of coloration, curved spine, erratic swimming, gradual wasting

Treatment

No cure exists; isolate affected fish to prevent spread, maintain pristine water conditions, consider euthanasia if severely affected

Bacterial Infection

Symptoms

Torn fins, open sores, cloudy eyes, loss of appetite

Treatment

Perform large water changes, maintain optimal water parameters, use broad-spectrum antibiotic treatment if condition worsens

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Quick Facts

pH
6.0–7.5
diet
omnivore
maxSize
1.75 inches
minTankSize
15 gallons
temperature
72–82°F (22–28°C)

Temperature

72–82°F

22–28°C

Stats

Community tips0
Kept by0 hobbyists