X-Ray Tetra
Pristella maxillaris
Description
The X-Ray Tetra is a small, transparent species of tetra that is notable for its unique, translucent body that allows aquarists to clearly see the internal structure of the fish, giving it its “X-ray” appearance. The fish has a pale, almost see-through body with a hint of yellow along the edges of the fins, particularly the dorsal and caudal fins. The fish has a slender body shape with a distinctive black stripe running horizontally along its midline, from its gills to its tail. Males tend to have more intense coloration in their fins, while females are usually slightly larger and rounder. The X-Ray Tetra is peaceful, social, and does well in schools, often seen swimming actively in the middle to upper parts of the tank.
Habitat Origin
Native to the clear, slow-moving rivers and streams of South America, particularly in Brazil and Colombia. X-Ray Tetras are typically found in areas with moderate water flow, submerged vegetation, and plenty of natural cover. These fish thrive in slightly acidic to neutral waters, mimicking the conditions of their native habitats.
Aquarium
Ideal Number in Aquarium: At least 6 individuals, as they are schooling fish and feel more secure in groups.
Favorite Food
X-Ray Tetras are omnivores and will accept a variety of foods. They can be fed high-quality flake food, micro pellets, and live or frozen foods like brine shrimp, daphnia, and bloodworms. They will also graze on algae and small plant matter in the tank. A varied diet will ensure they maintain their health, vibrant colors, and active behavior.
Behavior:
X-Ray Tetras are peaceful, active, and social fish that do well in schools. They feel more secure and display more natural behavior when housed in groups of at least 6. These fish are generally calm and do not exhibit any aggressive behavior, making them suitable for peaceful community tanks. They are active swimmers, often seen darting through the middle to upper sections of the tank, where their translucent bodies catch the light. Their non-aggressive nature makes them ideal for aquariums with other small, non-aggressive species.
Special Care:
X-Ray Tetras thrive in a well-planted aquarium with plenty of hiding spots, such as plants, driftwood, and rocks. A fine gravel or sandy substrate is ideal for them to forage naturally. Regular water changes and good filtration are essential to maintain clean water, as these fish are sensitive to poor water quality. X-Ray Tetras prefer slightly acidic to neutral water conditions and benefit from stable water parameters. They should not be exposed to extreme changes in temperature, pH, or water hardness.
Compatibility with Other Fish:
Yes, X-Ray Tetras are ideal for peaceful community tanks with other small, non-aggressive species. They can be kept with other tetras, rasboras, small catfish, and peaceful shrimp. Avoid keeping them with larger or aggressive fish, as these may intimidate or prey on them. Their peaceful nature and schooling behavior make them a great addition to mixed-species tanks.
Breeding Setup
A separate breeding tank is essential for X-Ray Tetras to control environmental conditions and protect the eggs and fry from predation. A 40-liter (10-gallon) tank is ideal, offering enough space and ensuring easier water maintenance. Preferred water conditions include a pH of 6.0–7.0, temperature of 24–28°C (75–82°F), and hardness of 2–10 dGH. A gentle sponge or internal filter ensures good aeration without disturbing eggs. For substrate, use fine gravel or go bare-bottom, and add Java moss, Hornwort, or duckweed to provide surfaces for eggs and replicate natural habitat. Use dim to moderate lighting, as bright light can stress the fish.
Conditioning for Breeding
To prepare X-Ray Tetras for spawning, offer a high-protein diet of live or frozen foods such as brine shrimp, daphnia, and bloodworms, along with quality flakes or pellets. This nutritional boost enhances their breeding readiness. Conduct 25% water changes every 2–3 days to maintain high water quality. Consistency in parameters is critical; stable temperature and clean water create an environment conducive to successful spawning.
Spawning Behavior
Spawning typically takes place early in the morning or late evening, triggered by optimal water conditions. X-Ray Tetras are egg-scattering fish; males will court and chase females who release 100–200 sticky eggs, which adhere to plants or the substrate. It is vital to remove the adult fish immediately after spawning, as they will likely eat the eggs or fry if left in the tank.
Fry Care
X-Ray Tetra eggs hatch within 24–36 hours, and the fry will absorb their yolk sacs for the first couple of days. Once free-swimming, start feeding them infusoria, liquid fry food, or rotifers, then gradually introduce baby brine shrimp or finely crushed flakes. Perform daily 10–15% water changes to maintain clean water and prevent ammonia buildup. Keep the temperature steady and ensure the water remains soft and well-oxygenated to support healthy fry growth.
Key Considerations
X-Ray Tetras reach sexual maturity at around 6–12 months of age. Males tend to be slimmer with more vivid coloration during courtship, while females are rounder, especially when gravid. Minimize stress by avoiding sudden changes in water temperature, pH, or lighting. A stable, peaceful environment is crucial for both breeding success and healthy fry development.