Tetras · Megalamphodus megalopterus

Black phantom tetra care guide

Also called: Black phantom

The black phantom tetra is a peaceful, 1.6 in (4 cm) tetra with a smoky body, a black shoulder spot and dark fins. Males put on harmless fin displays. Keep six or more in a planted 20 gallon (76 L) tank with soft, slightly acidic water.

Black phantom tetras need a tank of at least 20 gallons (76 L), a group of 6 or more, and water at 22–28°C (72–82°F) with a pH of 6–7.5. They grow to about 4 cm (1.6 in) and are peaceful.

Plan a tank with black phantom tetrasSee all tank mates

Black phantom tetra quick facts

Scientific nameMegalamphodus megalopterus
FamilyAcestrorhamphidae
OriginUpper Rio Guaporé (Madeira) and upper Rio Paraguay basins, Brazil and Bolivia (most are farm-bred)
Adult size4 cm (1.6 in)
Minimum tank20 gallons (76 L), at least 75 cm (30 in) long
Temperature22–28°C (72–82°F)
pH6–7.5
Hardness (GH)2–12 dGH
Group size6 or more (shoaling fish)
TemperamentPeaceful
Swims atMiddle
DietOmnivore
Care levelEasy
Lifespan3–5 years
Safe with shrimp?No, eats shrimp
Safe with plants?Yes

Tank setup

A 20 gallon (76 L) tank about 30 in (75 cm) long suits a group of six to eight. Live plants, driftwood, leaf litter and a dark substrate make them feel secure and deepen their color. Keep the light moderate and leave open water for swimming.

How many black phantom tetras in a tank?

The smallest common tank that suits black phantom tetras is a 20 gallon long. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.

TankBlack phantom tetras (alone)
3 gallonToo small
5 gallonToo small
10 gallonToo small
15 gallonToo small
20 gallonToo small
20 gallon long6–27
29 gallon6–39
40 gallon6–54
55 gallon6–74
75 gallon6–102
125 gallon6–170

What you need for black phantom tetras

Sized for a 20 gallon long tank, the smallest common size that suits a group of 6 black phantom tetras. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.

Tank and equipment

Food and extras for black phantom tetras

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Water parameters

Aim for 22–28 °C (72–82 °F), pH 6.0–7.5 and soft to moderately hard water around 2–12 dGH. Avoid sudden swings in temperature or chemistry. Change some water every week to keep nitrate low.

Best tank mates for black phantom tetras

These popular species share black phantom tetras' water needs and temperament. See the full list of 86 good matches.

Avoid keeping black phantom tetras with

  • Angelfish: Angelfish can eat black phantom tetras: they're small enough to fit in its mouth once it's grown.
  • Cherry shrimp: Black phantom tetra eats small shrimp like cherry shrimp.
  • Common goldfish: Common goldfish can eat black phantom tetras: they're small enough to fit in its mouth once it's grown.
  • Oscar: Oscar can eat black phantom tetras: they're small enough to fit in its mouth once it's grown.
  • Bala shark: Bala shark can eat black phantom tetras: they're small enough to fit in its mouth once it's grown.
  • Chinese algae eater: Chinese algae eater is aggressive and will bully or injure peaceful black phantom tetras.

Feeding

An easy-to-feed omnivore. Use flakes or nano pellets as the staple. Add frozen or live daphnia, bloodworm, mosquito larvae or brine shrimp several times a week for the best condition and color. It will also eat fry, baby shrimp and sometimes small adult dwarf shrimp.

Behavior

Calm and peaceful in a group, it swims mostly in the middle of the tank. Males spread their big black fins at each other in short sparring matches that rarely cause harm. Good tank mates are other small tetras, pencilfish, hatchetfish, corydoras, otocinclus, honey gouramis and dwarf cichlids. Watch them around slow, long-finned fish like bettas.

Breeding

Males have enlarged black dorsal, pelvic and anal fins. Females are deeper-bodied and have reddish pelvic, anal and adipose fins. Spawn a pair or group in a dim tank with soft, acidic water and java moss or mesh to protect the eggs. Remove the adults after spawning and feed the fry infusoria, then baby brine shrimp.

Tips from experienced keepers

  • Keep a mixed group of eight or more to see the males' fin displays at their best.
  • Dim light, floating plants and dark decor stop them looking pale.
  • Their sparring looks dramatic but rarely leads to damaged fins.
  • A long-fin form exists. It is slower, so keep it away from nippy fish.

Frequently asked questions

How many black phantom tetras should be kept together?

Keep at least six, and eight to ten if you have room. A mixed group of males and females shows the best color and behavior.

Can black phantom tetras live with shrimp?

It is risky. They eat baby shrimp and may pick off small adult cherry shrimp, so they are a poor choice for a shrimp breeding tank. Larger shrimp such as adult amanos are safer.

How can you tell male and female black phantom tetras apart?

Males have larger, all-black fins, especially a tall dorsal fin. Females are rounder and show red on the lower fins and the small fin near the tail.

Sources

We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.