Pristella maxillaris, commonly known as the X-ray tetra, is a species of freshwater fish that is native to the coastal waters of Venezuela, Guyana, Suriname, French Guiana, and northern Brazil. Its striking appearance and peaceful nature have made it a popular choice among hobbyists in the aquarium trade. Unfortunately, overfishing and habitat loss have contributed to a decline in their populations in the wild.
To meet the demand of the aquarium trade, Pristella maxillaris is now commercially bred in large numbers in various parts of the world. In the UK, the vast majority of these fish available for purchase are likely to come from breeding facilities in the Far East or Eastern Europe, where they are bred on a large scale for export. While it is rare to find wild-caught specimens for sale, there is still a need to ensure that the fish sold are sourced sustainably and that their origins are disclosed to consumers.
The X-ray tetra is a peaceful schooling fish that thrives in planted aquariums with plenty of swimming space. In the wild, they can be found in slow-moving or stagnant waters, such as ponds and swamps. Unfortunately, their natural habitat is threatened by deforestation, mining, and pollution. These environmental pressures have put the X-ray tetra at risk of extinction in the wild.
To preserve the species and promote sustainable practices, it is crucial to support responsible breeding practices and reduce the demand for wild-caught specimens. Consumers can play a significant role in this effort by only purchasing fish from reputable sources that prioritize ethical and sustainable practices. Additionally, it is essential to provide proper care for these delicate fish to ensure their health and longevity in the aquarium environment.
Pristella maxillaris is a species of freshwater fish that has adapted to various aquatic habitats in South America. During the dry season, it typically inhabits clearwater streams and tributaries. In these environments, the water is typically shallow, with moderate to fast-moving currents. X-ray tetras can be found in the upper reaches of the water column, where they feed on small invertebrates and plankton.
As the rainy season begins, the X-ray tetra moves into flooded areas of savannah, where it spawns amongst the submerged vegetation. These temporary floodplains are crucial to the survival of many aquatic species in the region, as they provide a rich source of food and shelter during periods of low water flow. The flooded savannahs are typically shallow, with slow-moving water and abundant plant growth. The X-ray tetra is well adapted to these conditions, with its streamlined body and ability to swim in tight shoals to avoid predators.
In the aquarium trade, X-ray tetras are typically kept in planted aquariums with plenty of swimming space and hiding places. They are known for their peaceful nature and schooling behavior, and are often kept with other small, non-aggressive fish. To recreate their natural habitat, it is recommended to provide them with live plants, moderate water flow, and a varied diet that includes small insects and crustaceans.
Overall, the X-ray tetra is a fascinating and adaptable species that has evolved to thrive in a range of aquatic habitats. By understanding their natural habitat and behavior, we can provide the best care for them in captivity and work to protect their populations in the wild.
Maximum Standard Length
The maximum standard length of Pristella maxillaris is typically around 40 to 45 millimeters. However, in rare cases, some individuals may grow slightly larger. It’s important to note that the size of these fish can be influenced by various factors, such as the quality of their diet, the size of their habitat, and their overall health and genetics.
In the aquarium trade, X-ray tetras are generally considered a small fish species, making them well-suited for smaller aquariums and community tanks. As schooling fish, they prefer to be kept in groups of at least six individuals, which allows them to display their natural behavior and feel secure in their environment.
Proper care and nutrition can help ensure that X-ray tetras reach their maximum potential size and live long, healthy lives. In the wild, these fish are known to feed on small invertebrates and plankton, so a varied diet that includes high-quality fish flakes, pellets, and live or frozen foods can help mimic their natural feeding habits. Additionally, maintaining water quality and providing a well-planted aquarium with plenty of hiding places can help reduce stress and promote overall health in these delicate fish.
When considering an aquarium for Pristella maxillaris, it’s important to keep in mind that these fish are active swimmers and are best kept in groups of at least six individuals. Additionally, their small size and peaceful nature make them a popular choice for community aquariums.
The recommended minimum aquarium size for a group of six X-ray tetras is around 60 cm in length, 30 cm in width, and 30 cm in height. This will provide enough swimming space for the fish and allow them to display their natural schooling behavior. It’s important to note that larger aquariums are always better, as they provide more space for the fish to explore and reduce the risk of water quality issues.
When setting up an aquarium for X-ray tetras, it’s important to provide a well-planted environment with plenty of hiding places and swimming areas. They prefer moderate to high water flow and a slightly acidic pH of around 6.0 to 7.0. Additionally, a good filtration system and regular water changes are necessary to maintain a healthy environment for these fish.
It’s also important to consider the other fish species in the aquarium when selecting tankmates for X-ray tetras. They are non-aggressive and generally do well with other small, peaceful fish, such as dwarf corydoras, neon tetras, and cherry shrimp. Avoid keeping them with larger or more aggressive fish, as this can cause stress and potentially lead to health issues.
Pristella maxillaris is a popular and adaptable fish that can thrive in a variety of aquarium setups. However, to truly appreciate the beauty of these fish, it’s recommended to create a natural and biologically appropriate environment that mimics their native habitat.
A heavily planted aquarium is a great option for X-ray tetras, as it provides plenty of hiding places and swimming areas. However, in very spartan setups, these fish may appear washed out and less vibrant. To bring out their best colors and natural behaviors, a biotope tank setup is an ideal option.
In a biotope tank, the aquarium is designed to mimic the natural environment of the X-ray tetra in the wild. A substrate of river sand and a few pieces of driftwood and twisted roots can create a natural and organic feel. Dried leaves, such as common beech or oak, can be added to the aquarium to stain the water a weak tea color and create a natural environment. Aquatic plants are not commonly found in the natural waters of X-ray tetras, but a few select species can be added for additional cover and aesthetic appeal.
A small net bag filled with aquarium-safe peat can be added to the filter to aid in the simulation of blackwater conditions. The dim lighting and weak tea-colored water will bring out the true beauty of these fish and create a stunning display that mimics their natural habitat.
Overall, X-ray tetras are a stunning and peaceful species that can be appreciated in a variety of aquarium setups. However, creating a biotope tank that mimics their natural environment can bring out their best colors and behaviors, and provide a unique and rewarding experience for both hobbyists and their fish.
Maintaining the proper water parameters is essential for the health and well-being of Pristella maxillaris. While these fish are adaptable to a range of conditions, it’s important to provide them with a stable and suitable environment to promote their natural behavior and longevity.
The optimal temperature range for X-ray tetras is around 22 to 28 °C, which is relatively warm compared to other freshwater fish species. In the wild, they are found in warm, tropical waters, so it’s important to maintain a consistent temperature in the aquarium to prevent stress and illness.
The pH range for X-ray tetras is relatively wide, with a recommended range of 6.0 to 7.5. This range is slightly acidic to neutral and mimics the pH of their natural habitat. However, it’s important to avoid sudden changes in pH, as this can cause stress and health issues for these delicate fish.
Hardness is not as critical for X-ray tetras, as their natural waters are subject to annual flooding, which can cause fluctuations in mineral content. Acceptable hardness ranges from 2 to 20°H, with no critical requirements. However, X-ray tetras breed during the wet season, when the water is naturally softer and more acidic. Therefore, a lower hardness level is preferred if you’re attempting to spawn these fish.
It’s important to monitor water parameters regularly and make adjustments as necessary to maintain a stable and healthy environment for X-ray tetras. Proper water chemistry and temperature can promote their natural behavior, encourage breeding, and prevent stress and illness.
Pristella maxillaris is a micropredator that feeds primarily on small invertebrates in its natural habitat. In the aquarium, these fish are generally unfussy and will readily accept a variety of different types of food.
A high-quality dried food, such as flakes or granules, can form the base of the X-ray tetra’s diet. These foods provide a good source of nutrition and can be supplemented with small live or frozen foods, such as Daphnia or Artemia. Offering a varied diet that includes both dried and live foods can help mimic the X-ray tetra’s natural feeding habits and promote optimal health and growth.
It’s important to avoid overfeeding X-ray tetras, as they have a small stomach and can be prone to obesity if they are fed too much. A good rule of thumb is to feed small amounts several times a day, rather than one large meal. Additionally, uneaten food should be removed from the aquarium promptly to prevent fouling of the water and maintain good water quality.
In addition to a varied diet, it’s also important to provide X-ray tetras with a well-planted aquarium that offers plenty of hiding places and swimming areas. These fish are social and prefer to be kept in groups of at least six individuals. A healthy and balanced diet, combined with proper care and environment, can help ensure that X-ray tetras thrive in the aquarium setting.
Behaviour and Compatibility
Pristella maxillaris, also known as the X-ray tetra, is a peaceful and social species that is best kept with other small and non-aggressive fish. These fish are shoaling by nature and prefer to be kept in groups of at least six individuals, preferably ten or more. When kept in smaller groups, they may become stressed and display abnormal behavior.
In a South American-themed aquarium, X-ray tetras can be combined with other small tetra species, pencil fish, hatchet fish, and dwarf cichlids such as Apistogramma. Additionally, Corydoras and small Loricariids can be good tankmates, as they are also peaceful and non-aggressive.
In a more general community aquarium, X-ray tetras can be combined with smaller rasboras, barbs, livebearers, loaches, Anabantoids, and West African dwarf cichlids such as Pelvicachromis species. It’s important to avoid keeping them with larger or more aggressive fish, as this can cause stress and potential health issues.
When selecting tankmates for X-ray tetras, it’s important to consider their temperament and behavior. They are a peaceful species and will not compete well with very boisterous or much larger tankmates. Additionally, it’s important to ensure that the aquarium is properly sized and well-planted to provide plenty of swimming space and hiding places for all of the fish.
Overall, X-ray tetras are a social and peaceful species that thrive when kept in a group with their own kind. Selecting appropriate tankmates and creating a suitable environment can promote their natural behavior and ensure their long-term health and well-being.
In Pristella maxillaris, also known as the X-ray tetra, there is a subtle but noticeable sexual dimorphism that can be observed in mature individuals. Females are usually slightly larger and noticeably stockier than males. This difference is more pronounced during the breeding season when females are carrying eggs.
In addition to the differences in size and body shape, there may be other subtle differences between males and females, such as differences in coloration or fin shape. However, these differences can be difficult to distinguish without close observation and may not be noticeable in all individuals.
It’s important to note that X-ray tetras are a peaceful and non-aggressive species that typically do well in groups of their own kind. When selecting a group of X-ray tetras for the aquarium, it’s recommended to choose individuals that are similar in size and appearance to promote harmonious social interactions.
Overall, while the sexual dimorphism in X-ray tetras may be subtle, it’s still an important factor to consider when selecting and observing these fish in the aquarium setting.
Breeding Pristella maxillaris, also known as the X-ray tetra, can be relatively easy, but raising the tiny fry can be a bit challenging. To successfully breed and raise X-ray tetra fry, a dedicated tank setup is needed. An 18″ x 10″ x 10″ tank size should be sufficient, and it should be very dimly lit and contain clumps of fine-leaved plants such as java moss or spawning mops to give the fish somewhere to deposit their eggs. Alternatively, a mesh covering the base of the tank can be used to prevent adults from reaching the eggs. The water should be soft and acidic with a pH range of 5.5-6.5 and gH of 1-5, with a temperature of around 80-84°F. Filtering the water through peat and using RO water can be beneficial. A small air-powered sponge filter is all that’s needed for filtration.
X-ray tetras can be spawned in a group, with six specimens of each sex being a good number. The adults can be conditioned with plenty of small live foods, and spawning should not present too many problems. Once eggs are visible, the adults can be removed, or if the tank is heavily planted, left in situ, and fry siphoned from the tank as they’re noticed.
For optimal productivity, it’s best to spawn X-ray tetras in pairs. In this technique, male and female groups are conditioned in separate tanks or via the use of a tank divider. When the females are noticeably full of eggs and the males are displaying their best colors, the fattest female and best-colored male are selected and transferred to the spawning tank in the evening. They should spawn the following morning. If no eggs appear after a couple of days, they should be removed, and a different pair should be tried.
Regardless of the breeding method used, the adults will eat the eggs given the chance and should preferably be removed as soon as eggs are noticed. The eggs will hatch in 24-36 hours, with the fry becoming free-swimming 3-4 days later. The fry should be fed on an infusoria-type food for the first few days until they’re large enough to accept microworm or brine shrimp nauplii. Both eggs and fry are light-sensitive in the early stages of life, and the tank should be kept in darkness if possible.
Overall, breeding and raising X-ray tetras can be a rewarding experience, but it requires careful attention to water parameters and tank setup, as well as a proper diet and appropriate care for the delicate fry.
Pristella maxillaris is a highly popular species in the aquarium hobby and is readily available in most aquatic shops. It is often considered one of the best choices for newcomers to fishkeeping due to its peaceful nature, hardiness, and affordability. A selectively bred “golden” strain is also available, which is a semi-albino variety of the fish. Care for this strain is much the same as for the standard form of the species.
Currently, Pristella maxillaris is the only species in its genus. However, in older literature, it was sometimes referred to by the now invalid name Pristella riddlei. Additionally, this species may be sold under different common names, including “pristella tetra” and “water goldfinch.”
Overall, Pristella maxillaris is an excellent choice for aquarists of all skill levels, and its popularity in the hobby reflects its many desirable qualities as a peaceful and hardy fish.
4 Responses to “Pristella maxillaris – X-ray Tetra”
November 17th, 2012 at 2:36 pm
I would like to share my personal experience with keeping Pristella maxillaris for over three years. I have a dedicated aquarium with a black background and dark substrate, and I have noticed that the transparency in the fish is now almost completely gone. Instead, they exhibit a grayish body with a vivid red tail. In my observation, the males have a darker gray color and more vivid colors than the females, and they also appear to be slightly larger in length.
Based on my experience, I would recommend a minimum aquarium size of 60*30cm for Pristella maxillaris as they can be quite active at times. In my tank, I keep them with Neocaridina shrimps, and I have not observed any instances of the fish eating the adult shrimps.
March 26th, 2013 at 3:37 pm
In my 75-gallon community tank, I have 11 gold Pristella maxillaris, and I have noticed that they do not eat at the surface but prefer to feed mid-tank or at the bottom. To accommodate their feeding habits, I set my filter on the lowest flow and release a pinch of food mid-tank. Additionally, I have observed that they are more comfortable eating with the light off.
Overall, I have found this feeding method to be effective in ensuring that my gold Pristellas receive enough food. They are excellent fish and have been a great addition to my community tank.
November 11th, 2015 at 1:25 am
Hello! I have five of these fish, and when I first got them, they had a silver sheen over their belly, as seen in pictures. However, I have noticed that a couple of them are now showing a redness that resembles the color of blood. Despite this, they seem to be their lively selves and are eating normally. Do you have any ideas about what could be causing this change in color?