X-Ray Tetra (Pristella)

Pristella maxillaris

Characins

A remarkably hardy and peaceful schooling fish, named for its translucent body that reveals its internal organs. Uniquely among tetras, it naturally inhabits both fresh and slightly brackish coastal waters in South America, making it incredibly adaptable to various aquarium conditions. An excellent choice for beginners.

At a Glance

Adult Size5 cm
Body ShapeCompressed
Growth RateModerate
TemperamentPeaceful
Water TypeBrackish Tolerant
Flow PreferenceModerate
Waste OutputLow
StockingSchool of 6+

Tank Requirements

Minimum Volume60 L
Minimum Length60 cm
FlowModerate
Water TypeBrackish Tolerant
Must-Haves in the Tank
Plants - Densely covered

Find the right tank equipment

Browse tanks, décor, and equipment suited for this setup.

Water Parameters

Temperature2328°C
pH68
Hardness220 dGH

Shop water care essentials

Keep water parameters stable with the right testing and heating gear.

Temperament & Compatibility

Aggression LevelPeaceful
1/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least6 fish
Max per TankNo limit
Can Live Alone?No — needs a group
Behavior Traits
Hyperactive / Fast SwimmerNano / Bite-sized (Predation Risk)Fry Predator

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Standard

The classic X-Ray Tetra featuring a clear body with striking black, yellow, and white banded dorsal and anal fins, finished with a red tail.

Same care requirements as the base species

Also known as: Translucent, Wild Type

Golden / Albino

A popular color morph lacking dark pigmentation. It features a golden/pinkish translucent body with pale fins and red eyes. Shares the same extreme hardiness as the standard form.

Same care requirements as the base species

Also known as: Albino Pristella, Gold Pristella, Pink

Balloon

A selectively bred 'shortbody' mutation. Their compressed, rounded spine makes them weaker swimmers. They require gentler currents and are more prone to swim bladder issues.

Differs in 2 traits from base species

Also known as: Balloon Pristella, Shortbody

Adult Size4 cm
FlowLow

X-Ray Tetra (Pristella) Care Guide Summary

The X-Ray Tetra (Pristella), scientifically known as Pristella maxillaris, belongs to the Characins family group. Adults reach a maximum size of approximately 5 cm and have a compressed body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a low level of biological waste.

To thrive, the X-Ray Tetra (Pristella) requires a brackish tolerant aquarium with a minimum volume of 60 litres and a tank length of at least 60 cm. Water temperature should be maintained between 23°C and 28°C, with a pH range of 68 and a general hardness of 220 dGH. A moderate water flow is preferred. An aquarium test kit can help you monitor these values.

The X-Ray Tetra (Pristella) is a rewarding species to keep, provided its core environmental needs are met. This species is available in 3 varieties: Standard, Golden / Albino, and Balloon. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.

X-Ray Tetra (Pristella) Habitat Setup

When setting up an aquarium for the X-Ray Tetra (Pristella), a moderate water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include dense planting to provide cover, break sightlines, and reduce stress.

X-Ray Tetra (Pristella) Compatibility Notes

Classified as peaceful, the X-Ray Tetra (Pristella) is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. When choosing tankmates, their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.

Frequently Asked Questions About X-Ray Tetra (Pristella)

How big does X-Ray Tetra (Pristella) get?+
X-Ray Tetra (Pristella) (Pristella maxillaris) typically reaches a maximum adult size of approximately 5 cm. They have a compressed body shape and a moderate growth rate.
What tank size does X-Ray Tetra (Pristella) need?+
A minimum aquarium volume of 60 litres and a tank length of at least 60 cm are recommended for X-Ray Tetra (Pristella). This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does X-Ray Tetra (Pristella) need?+
X-Ray Tetra (Pristella) thrives in brackish tolerant conditions with a temperature range of 23–28°C, a pH between 6 and 8, and a general hardness of 2–20 dGH. A moderate water flow is preferred.
Is X-Ray Tetra (Pristella) peaceful or aggressive?+
X-Ray Tetra (Pristella) is classified as peaceful with an aggression score of 1 out of 10. They are generally well-suited to peaceful community tanks.
How many X-Ray Tetra (Pristella) should be kept together?+
X-Ray Tetra (Pristella) is a schooling species and should be kept in groups of at least 6. Larger groups help distribute aggression and encourage natural schooling behaviour.
Does X-Ray Tetra (Pristella) have any special tank requirements?+
Yes. X-Ray Tetra (Pristella) benefits from plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.

Similar Species

Cardinal Tetra

Paracheirodon axelrodi

Characins
4 cm Peaceful

A stunning schooling fish native to the upper Orinoco and Rio Negro basins in South America. Famous for its brilliant iridescent blue line and a vivid red stripe that extends the full length of its body (distinguishing it from the Neon Tetra). They are strictly schooling fish that thrive in warm, acidic blackwater environments.

Glowlight Tetra

Hemigrammus erythrozonus

Characins
4 cm Peaceful

A peaceful, schooling nano fish native to the Essequibo River basin in South America. They are famous for their translucent bodies and the striking iridescent neon-orange stripe running from snout to tail. They thrive in mature, planted aquariums with slightly soft, acidic water and subdued lighting.

Lemon Tetra

Hyphessobrycon pulchripinnis

Characins
5 cm Peaceful

A peaceful, deep-bodied schooling tetra known for its translucent yellow coloration and striking black and yellow fins. They are robust and active, making them an excellent choice for planted community aquariums. Their colors intensify significantly in a well-established tank with a dark substrate and proper schooling numbers.

Serpae Tetra

Hyphessobrycon eques

Characins
4.5 cm Semi-Aggressive

A striking, deep-red schooling fish known for its highly active nature. While hardy and beautiful, Serpae Tetras are notorious fin-nippers. This behavior is usually localized within their own pecking order if kept in large enough schools (8+), but they should never be housed with slow-moving or long-finned tank mates like Bettas, Angelfish, or Gouramis.

Diamond Tetra

Moenkhausia pittieri

Characins
6 cm Peaceful

A stunning, deep-bodied tetra endemic to Lake Valencia in Venezuela. Named for the brilliant, iridescent scales on its flanks that sparkle like diamonds under the right lighting. They are highly active, peaceful schooling fish that thrive in well-planted aquariums. Males develop spectacular, flowing fins as they mature.

Emperor Tetra

Nematobrycon palmeri

Characins
5 cm Peaceful

A striking, robust schooling fish from Colombia. Unlike many tetras, they do not swim in a tight shoal, preferring to loosely associate while males stake out small territories to display to females. They feature a bold black lateral line and iridescent purple/blue hues.