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FishbeginnerFreshwater

X-Ray Tetra

Pristella maxillaris

AnimaliaChordataActinopterygiiCharaciformesCharacidae

📍 Amazon and Orinoco basins, Venezuela and Brazil

Ask Finn

The X-ray tetra (also called the pristella tetra) has a nearly transparent body through which the spine and organs are clearly visible — hence the name. Its dorsal and anal fins are boldly banded in black, white, and yellow. It is an extraordinarily adaptable species that tolerates both soft acidic and hard alkaline water, making it one of the hardiest tetras available.

Size1.75"
Min Tank15g
School6+
peaceful
Zonemid

Care Guide

Diet

X-Ray Tetras are omnivores that thrive on high-quality flake foods and micro pellets as staples. Supplement 2-3 times weekly with frozen foods such as brine shrimp, daphnia, or bloodworms to enhance coloration and promote optimal health. Feed small amounts once daily, only what they can consume in 2-3 minutes.

Behavior

X-Ray Tetras are active, peaceful schooling fish that exhibit constant motion in the mid-water column, creating dynamic visual interest in planted tanks. They are non-aggressive toward tankmates and show reduced stress and enhanced coloration when kept in groups of 8 or more. They are most active during dawn and dusk, displaying natural schooling behavior that makes them excellent community fish.

Breeding

Breeding X-Ray Tetras in captivity is moderately difficult and rarely achieved in home aquariums. They require soft, acidic water (pH 5.5–6.5), dense vegetation or spawning mops, and careful separation of breeding pairs. Fry are extremely small and require infusoria or liquid fry food for the first week before accepting micro pellets.

Common Diseases

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots on body and fins, rapid breathing, flashing against decorations, lethargy

Treatment

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

Fin Rot

Symptoms

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

Treatment

Improve water quality with frequent partial water changes, reduce stocking density, treat with antibacterial medication if severe; ensure temperature stays 24–26°C

Neon Tetra Disease (Pleistophora)

Symptoms

Loss of coloration, curved spine, lethargy, erratic swimming behavior, white spots along lateral line

Treatment

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

Columnaris (Flexibacter columnaris)

Symptoms

Cottony growth on mouth and gills, rapid breathing, loss of appetite, fin deterioration

Treatment

Perform 50% water change immediately, treat with antibacterial medication, maintain temperature at 24–26°C, improve water quality and reduce stress

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Quick Facts

diet
Omnivore – flake, micro pellets, frozen foods
schooling
8+ recommended
tank size
15 gallons minimum
temperament
Peaceful schooling fish – suitable for most communities

Water it likes

ph
6.0–8.0
hardness
5–20 dGH
temperature
72–82°F (22–28°C)

Stats

Community tips0
Kept by0 hobbyists