Product Details

X-ray Tetra – Pristella maxillaris

The X-ray Tetra is a hardy, peaceful South American tetra with a translucent body, subtle golden sheen and bold black, white and yellow fin markings. Also known as the Pristella Tetra, Pristella maxillaris is one of the more adaptable community tetras, making it a reliable choice for mature planted aquariums. Kept in a proper group, it is active, attractive and well suited to peaceful community displays.

Key Identification:

Common Name: X-ray Tetra
Other Names: X-Ray Tetra, Pristella Tetra, Golden Pristella Tetra, Water Goldfinch
Scientific Name: Pristella maxillaris
Fish Type: Tetra / Characin
Water Type: Freshwater

Natural Range & Habitat:

Pristella maxillaris is native to South America, including the Amazon, Orinoco and coastal river drainages of the Guianas. In nature, it is associated with calm freshwater habitats, including densely vegetated swampy areas and quieter waters.

In the aquarium, X-ray Tetras do well in planted community setups with clean water, open swimming space and shaded cover. They are more adaptable than many delicate blackwater tetras, but they still benefit from a mature aquarium with stable water quality and calm surroundings.

Appearance & Adult Size:

X-ray Tetras have a slim, lightly translucent body that can show a faint golden or silvery sheen under aquarium lighting. The dorsal and anal fins are attractively marked with black, white and yellow, while the tail may show a touch of red or orange. Their semi-transparent body gives rise to the “X-ray” common name.

Adults usually reach around 4–5 cm. Mature females are usually fuller-bodied, while males tend to be slimmer and may show a more pointed swim bladder profile when viewed closely.

Aquarium Suitability:

This is an excellent community fish for mature tropical aquariums. X-ray Tetras suit planted displays, mixed tetra communities and peaceful general aquariums. They are active without being overly boisterous, and their hardiness makes them a good option for customers wanting a forgiving shoaling tetra.

They are not suitable for aggressive cichlid tanks, large predators, tiny unfiltered tanks or aquariums with very nippy fish that may damage their fins.

Recommended Aquarium Size:

A practical minimum is 60 litres for a small group, with a tank length of at least 60 cm recommended. Larger aquariums of 75–90 litres or more are preferred for bigger groups and mixed community setups.

Keep in a group of at least 6, with 8–10 or more preferred. Larger groups are more confident, show better behaviour and create a more natural display.

Water Conditions:

Temperature: 24–28°C
pH: 6.0–8.0
Hardness: Soft to hard; adaptable if stable
Additional Notes: X-ray Tetras are tolerant compared with many small tetras, but they still need clean, stable water. Keep ammonia and nitrite at zero, maintain low nitrate and avoid sudden changes in temperature or chemistry. They can adapt to a wider hardness range than many Amazonian tetras, provided acclimation is careful.

Temperament & Tank Mates:

Aquarium Category: Community Fish

X-ray Tetras are peaceful, gregarious community fish. Suitable tank mates include other peaceful tetras, rasboras, danios, small barbs, Cory-type catfish, Otocinclus, bristlenose plecs, dwarf cichlids with care, honey gouramis and calm livebearers in compatible water.

Avoid large predatory fish, aggressive cichlids, severe fin-nippers and very boisterous species that may outcompete them. They should not be kept singly or in pairs, as group life is important for confidence and natural behaviour.

Feeding:

X-ray Tetras are easy-feeding omnivores. Offer quality fine flakes, micro pellets or small granules as the staple diet. Supplement with frozen or live foods such as daphnia, cyclops, brineshrimp, mosquito larvae and small bloodworm.

A varied diet helps maintain condition, fin colour and activity. Feed small portions that are eaten quickly, as they are active midwater feeders and will usually respond readily at feeding time.

Behaviour in the Aquarium:

This species usually swims in the middle and upper levels of the aquarium, moving in a loose group through open water and around plant cover. It is peaceful, active and rarely troublesome when kept in proper numbers.

X-ray Tetras are egg scatterers and do not provide parental care. If spawning occurs in a community aquarium, eggs and fry are usually eaten unless a separate breeding setup is used.

Care Notes:

Add X-ray Tetras only to a mature, fully cycled aquarium. Provide plant cover, open swimming space and regular water changes. Although hardy, they should not be used to cycle a new aquarium or kept in poor water quality.

This is a good beginner-friendly tetra when the tank is established, the group is large enough and tank mates are peaceful.

Recommended For:

Beginner to intermediate

Availability:

Common / Usually captive-bred or farmed

Image Disclaimer:

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Natural variation in size, body transparency, gold sheen, fin colour and markings can occur between individual fish.