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X-Ray Tetra (Pristella maxillaris)

The X-Ray Tetra, scientifically known as Pristella maxillaris, is a captivating and popular fish among aquarium enthusiasts. Originating from the Amazon River’s coastal waters, this species is renowned for its unique, almost transparent body and peaceful nature, making it a preferred choice for community tanks.

X-Ray Tetra Facts

Fact Detail
Scientific Name Pristella maxillaris
Common Names X-Ray Tetra, Pristella Tetra, Gold Pristella Tetra
Family Characidae
Origin Coastal waters of the Amazon River
Adult Size Up to 2 inches (5 cm)
Lifespan Approximately 5 years
Body Shape Small, translucent body with a unique skeletal structure visible
Coloration Translucent with hues of yellow, black, and white; red tail
Water Conditions pH 6.0 – 8.0, Temperature 75°F – 82°F (24°C – 28°C)
Tank Size Minimum 10 gallons
Diet Omnivorous – Flake food, brine shrimp, daphnia
Behavior Peaceful, schooling fish
Compatibility Good for community tanks with other small, peaceful fish

X-Ray Tetra Profile

Belonging to the Characidae family, X-Ray Tetras are small, typically reaching up to 2 inches in length. They have a lifespan of about 5 years, provided they’re kept in optimal conditions. These fish are known for their hardiness and adaptability, making them suitable for both novice and experienced fish keepers.

X-Ray Tetra Coloring

One of the most striking features of X-Ray Tetras is their translucent body, through which you can often see their spine and internal organs. They display a mix of yellow, black, and white colors, with a prominent black line running along their body and a splash of red near the tail, adding to their visual appeal.

X-Ray Tetra Habitat

X-Ray Tetras originate from the Amazon River Basin in South America. They inhabit clear and blackwater streams and rivers, preferring areas with dense vegetation. These environments provide both shelter and abundant food sources, contributing to their unique translucent appearance and agile swimming abilities.

X-Ray Tetra Aquarium Setup

Setting up the right environment for X-Ray Tetras is crucial for their health and wellbeing. These small, peaceful fish thrive in a well-planned aquarium that mimics their natural habitat.

  • Tank Size and Type

A minimum of a 10-gallon tank is recommended for X-Ray Tetras. They are active swimmers and enjoy space to move around. A larger tank is even better, especially if you plan to keep a school of them, as they are social fish and prefer living in groups.

  • Water Conditions

Pristella Tetra thrive in soft, slightly acidic water. Aim for a pH level between 6.0 and 8.0 and maintain water temperatures between 75°F and 82°F (24°C – 28°C). Regular water changes are necessary to keep nitrate levels low and maintain water quality.

  • Filtration and Aeration

A good filtration system is essential to keep the water clean and free of harmful toxins. However, X-Ray Tetras do not like strong currents, so it’s important to have a filter that doesn’t create too much water movement. An air pump can be added to ensure adequate oxygenation of the water.

  • Lighting and Substrate

Standard aquarium lighting is sufficient for Pristella Tetras. They are not overly sensitive to light, but they do appreciate some darker areas in the tank. A dark-colored substrate can help mimic their natural environment and make them feel more at home.

  • Plants and Decorations

Plants are an important aspect of the X-Ray Tetra’s environment. They provide hiding spots and help keep the fish comfortable. Use live plants like Java Fern, Anubias, or Amazon Sword plants. Decorations and driftwood can also be added to provide additional hiding spaces and create a more natural-looking environment.

  • Water Chemistry and Maintenance

Regular testing of the water parameters is vital to ensure the tank remains a healthy environment for your X-Ray Tetras. Ammonia and nitrite levels should always be at zero, with nitrates kept as low as possible. Regular partial water changes, typically 10-20% weekly, are recommended to maintain optimal water conditions.

X-Ray Tetra Breeding

Breeding Pristella Tetras can be a fascinating experience for aquarium hobbyists. These fish require specific conditions to breed successfully.

Breeding Environment

Setting up a dedicated breeding tank is crucial. This tank should be about 10 gallons, with soft, slightly acidic water (pH 6.0-6.5). The temperature should be slightly warmer than their regular tank, around 78°F to 80°F. Dim lighting and the presence of fine-leaved plants or a spawning mop are important to encourage spawning. A sponge filter is recommended to keep the water clean without creating strong currents.

Spawning Process

To initiate spawning, condition the breeding pair with high-quality foods, such as live or frozen brine shrimp and bloodworms. Once the female is noticeably fuller, indicating egg carrying, introduce the pair to the breeding tank. Spawning typically occurs in the morning. The female scatters eggs among the plants, which the male then fertilizes. After spawning, remove the adult fish to prevent them from eating the eggs. The eggs will hatch in about 24 hours, and the fry will become free-swimming a few days later. Initially, feed the fry with infusoria or specially formulated fry food until they are large enough to eat crushed flakes or micro worms.

X-Ray Tetra Diet & Feeding

Gold Pristella Tetra are omnivorous and not particularly picky eaters. A diet consisting of high-quality flake food, along with occasional treats like brine shrimp or daphnia, will ensure they receive the necessary nutrients. Feed them small amounts 2-3 times a day to avoid overfeeding.

X-Ray Tetra Compatibility

As peaceful fish, Pristella Tetras do well in community tanks. They are best kept in groups of at least six, as they are schooling fish and thrive in the company of their own kind. They are compatible with Pencil Fish, Mollies, Guppy Fish, Barbs, Kuhli Loaches, Harlequin Rasbora, Red Eye Tetra, Neon Tetra, Swordtail, Zebra Danio, White Cloud, Dwarf Gourami, Lemon Tetra and Black Phantom Tetra. Avoid keeping them with large or aggressive species, as they can become stressed or preyed upon.

X-Ray Tetra Common Diseases

X-Ray Tetras are generally hardy, but like all fish, they are susceptible to certain diseases. The most common issues include Ichthyophthirius Multifiliis, commonly known as Ich or white spot disease, characterized by white spots on the skin and fins. They can also suffer from fungal infections, evident as white cottony growths, and bacterial infections, which often manifest as fin rot or ulcers. Good tank maintenance, proper diet, and regular water changes are crucial in preventing these diseases. If a disease does occur, early diagnosis and treatment are key to successful recovery.


In summary, X-Ray Tetras are a fascinating and relatively easy-to-care-for species that can add beauty and intrigue to any freshwater aquarium. Their peaceful nature and striking appearance make them a favorite among aquarists. With proper care, they can be a delightful addition to your aquatic family.