Hyphessobrycon haraldschultzi (TRAVASSOS, 1960) – Crystal Red Tetra

Synonyms

Hemigrammus haraldschultzi is a synonym for Hyphessobrycon haraldschultzi. The species was first described by Dr. Heraldo Antonio Britski and Dr. Sergio Macedo Zago in 1999.

The scientific name of the Crystal Red Tetra was previously known as Hemigrammus haraldschultzi, but it was later changed to Hyphessobrycon haraldschultzi in 2003 by Dr. Jorge Casciotta and Dr. Adriana Almirón. The species was named after the famous German aquarium fish breeder Harald Schultz, who was known for his expertise in breeding tetras.

Synonyms are scientific names that were used previously to describe a particular species, but have been replaced by the currently accepted scientific name. In the case of the Crystal Red Tetra, Hemigrammus haraldschultzi was the previously accepted scientific name, but it was later replaced by Hyphessobrycon haraldschultzi.

It is not uncommon for species to have multiple synonyms, especially when taxonomic classifications are constantly evolving and changing as new information becomes available. However, it is important to use the currently accepted scientific name to avoid confusion and ensure accuracy in scientific research and conservation efforts.

Etymology

Hyphessobrycon is a genus of freshwater fish that belongs to the family Characidae. The name Hyphessobrycon is derived from the Ancient Greek word ‘υπελάσσων’ (hyphesson), which means ‘of lesser stature’, and is used as a prefix in this case to describe the smaller size of these fish. The second part of the name, ‘Brycon’, refers to the generic name of the fish.

The specific epithet ‘haraldschultzi’ refers to the famous Brazilian ethnologist Harald Schultz, who made significant contributions to the study of Amazonian indigenous cultures. The Crystal Red Tetra was named in his honor for his expertise in breeding tetras and his contributions to the aquarium hobby.

Naming a species after a person is a great honor and a testament to their contributions and achievements in their respective field. In the case of the Crystal Red Tetra, Harald Schultz’s expertise in breeding tetras made him a worthy namesake for this beautiful and popular fish species.

The scientific name of the Crystal Red Tetra, Hyphessobrycon haraldschultzi, reflects the smaller size of this fish and honors the contributions of a distinguished Brazilian ethnologist and tetra breeder.

Classification

Hyphessobrycon haraldschultzi belongs to the order Characiformes, which is a diverse and widespread group of freshwater fish that includes popular aquarium species such as tetras, hatchetfish, and piranhas.

The family Characidae is a group of fish within the Characiformes order that includes many of the most popular freshwater aquarium fish species, such as neon tetras, black tetras, and the Crystal Red Tetra. Characidae fish are known for their colorful and varied appearance, streamlined body with a small adipose fin, elongated anal fin, and unique set of teeth known as tetraodontiform teeth.

Hyphessobrycon haraldschultzi is part of the genus Hyphessobrycon, which is a group of small characids known for their peaceful nature and attractive appearance. They are typically found in South America and are popular among aquarium hobbyists for their bright colors and active behavior. Within the genus Hyphessobrycon, H. haraldschultzi is part of the H. eques group, which is characterized by the presence of a prominent dark marking on the dorsal fin.

Distribution

Hyphessobrycon haraldschultzi is a species of freshwater fish that is endemic to the rio Araguaia system, which is the major tributary of the rio Tocantins within the lower Amazon basin in central and western Brazil. While the exact range of this species within the drainage is not fully understood, it is known to occur in this region.

The type locality for Hyphessobrycon haraldschultzi is the ‘Ilha do Bananal, Goiaz, Brazil’, which refers to Bananal Island. This island is the largest fluvial island in the world and is formed from the bisection of the Araguaia in southwestern Tocantins state. This location provides a unique habitat for the Crystal Red Tetra and may play a role in its unique physical characteristics and behavior.

After the bifurcation of the river, the eastern arm is often referred to as the rio Javaés. It is probable that the type series of Hyphessobrycon haraldschultzi was collected there, since the Javaés runs through a portion of Goiás state. This area is known for its diverse aquatic life and unique ecological features, which may contribute to the survival and adaptation of this species.

Hyphessobrycon haraldschultzi’s range within the rio Araguaia system and its unique habitat on Bananal Island and the rio Javaés, highlight the importance of preserving these areas and their diverse aquatic life. The Crystal Red Tetra is a valuable part of this ecosystem and adds to the biodiversity and beauty of the region.

Habitat

While there is limited information available about the habitat of the Hyphessobrycon haraldschultzi, it is presumed to inhabit minor tributaries, backwaters, and oxbow lakes, rather than the main river channels. These habitats provide a more stable and secluded environment for the Crystal Red Tetra to thrive.

In the Araguaia drainage, the habitats where this species is found typically contain soft, weakly acidic water. The substrate is covered by a layer of fallen leaves and branches, which provides a natural environment for the fish and their prey. These conditions allow for the growth of a diverse range of aquatic plants and microorganisms, which contribute to the overall health of the ecosystem.

The preferred habitat of the Crystal Red Tetra highlights the importance of preserving the natural environment and protecting the delicate balance of aquatic ecosystems. By maintaining suitable water conditions and providing a diverse range of habitats for fish species like the Crystal Red Tetra, we can help ensure the continued survival and biodiversity of our planet’s aquatic life.

Maximum Standard Length

The maximum standard length of the Hyphessobrycon haraldschultzi, also known as the Crystal Red Tetra, is between 20-25 mm. Despite their small size, these fish are highly prized for their striking red and white coloration, which adds vibrancy and beauty to any aquarium.

Their small size also makes them a great choice for smaller tanks and nano aquariums, allowing for the creation of unique and eye-catching aquatic displays. Despite their diminutive size, these fish are active and social, making them a joy to watch and interact with.

Their small size also makes them relatively easy to care for, as they require less food and produce less waste than larger fish species. This makes them an ideal choice for beginner hobbyists who are just starting out in the aquarium hobby.

The small size of the Crystal Red Tetra is a testament to the diversity and beauty of the aquatic world, proving that even the smallest fish can have a big impact in the world of aquariums.

Aquarium Size

The recommended minimum aquarium size for the Crystal Red Tetra is 60 x 30 cm or equivalent. This size provides enough swimming space and allows for a school of 6-8 individuals to thrive. It is important to provide adequate space to prevent overcrowding, which can lead to stress and health issues in fish. A larger aquarium size can also help maintain stable water conditions and reduce the need for frequent water changes.

Additionally, a larger aquarium size allows for more flexibility in aquascaping, creating a more natural and visually appealing environment for the Crystal Red Tetra.

Providing the appropriate aquarium size is an important factor in ensuring the long-term health and well-being of the Crystal Red Tetra in captivity.

Maintenance

The Crystal Red Tetra is best suited for an aquarium setup with a sandy substrate and driftwood roots and branches. They also thrive in a planted tank, with floating plants being a useful addition to the aquarium as they provide shade and cover for the fish.

Dried leaf litter can also be beneficial to the aquarium as it promotes the establishment of microbe colonies, serving as a valuable secondary food source for fry. The humic substances released by the decaying leaves can also be beneficial to the overall health of the aquarium.

Filtration for the Crystal Red Tetra needs to be gentle, and an air-powered sponge-style unit is usually adequate. A degree of water movement is acceptable and can help maintain stable water conditions.

Providing a suitable environment with proper substrate, decoration, and filtration is essential to the health and well-being of the Crystal Red Tetra in captivity. By providing the necessary elements in their aquarium, hobbyists can help create a healthy and thriving environment for these peaceful and delightful fish.

Water Conditions

Maintaining suitable water conditions is crucial for the health and well-being of the Crystal Red Tetra in captivity.

The ideal temperature range for these fish is 20-28 °C, and maintaining a stable water temperature within this range is essential.

In addition to temperature, the pH level of the water is also important for the Crystal Red Tetra. They prefer a pH range of 5.0-7.0, and deviations from this range can cause stress and health issues in the fish.

The hardness of the water is another important factor to consider when caring for the Crystal Red Tetra. They thrive in a hardness range of 18-179 ppm, and maintaining stable water hardness within this range is important for their overall health and well-being.

Providing suitable water conditions also involves monitoring and maintaining water quality parameters such as ammonia, nitrite, and nitrate levels. High levels of these compounds can be toxic to fish and can lead to health issues or even death.

In brief, maintaining appropriate temperature, pH, hardness, and water quality levels is essential to the long-term success and well-being of the Crystal Red Tetra in the aquarium. Regular testing and maintenance of these parameters will help ensure a healthy and thriving aquarium environment for these beautiful fish.

Diet

The Crystal Red Tetra is an omnivorous species that feeds on a variety of small invertebrates, crustaceans, filamentous algae, and fallen fruit in nature.

In the aquarium, they can survive on a diet of dried foods, but they will thrive when offered a varied menu that includes live and frozen foods.

Chironomid larvae (bloodworm), mosquito larvae, Daphnia, Moina, and other small invertebrates can be provided as live or frozen foods. These foods provide essential nutrients that may not be available in dried foods.

Offering a varied diet also helps prevent boredom and encourages natural foraging behaviors in the Crystal Red Tetra. This can help reduce stress and promote overall health and well-being.

It is important to note that overfeeding should be avoided, as this can lead to health issues and pollute the aquarium water. A general rule of thumb is to feed small amounts several times per day, rather than one large feeding.

Providing a balanced and varied diet is an important factor in maintaining the long-term health and well-being of the Crystal Red Tetra in captivity. By offering a variety of foods, hobbyists can help ensure that their fish receive all the necessary nutrients for optimal health and vitality.

Behaviour and Compatibility

The Crystal Red Tetra is a docile fish that thrives in community aquariums, making it a suitable addition to any well-researched fish community.

When considering tankmates, it is recommended to keep them alongside similarly-sized characids, gasteropelecids, lebiasinids, smaller callichthyid or loricariid catfishes, and non-predatory, small-to-medium-sized cichlids.

To ensure a comfortable social environment, hobbyists are advised to purchase a mixed-sex group of at least 8-10 specimens. Adding other schooling fish can provide a sense of security and create a more natural-looking display in the aquarium.

Due to their peaceful nature, the Crystal Red Tetra is an excellent choice for beginner hobbyists or those looking to add a calming presence to their aquarium. Their tranquil temperament also makes them an ideal choice for a community aquarium.

On the whole, the Crystal Red Tetra is a delightful and peaceful fish that adds beauty and tranquility to any aquatic display.

Sexual Dimorphism

As Crystal Red Tetras mature, females tend to develop a larger and more rounded body shape than males. This difference in size is most noticeable in the abdominal region, where females appear plumper than males. Additionally, during breeding periods, female Crystal Red Tetras may display a brighter red coloration than males.

These physical differences between the sexes are important for hobbyists who wish to breed Crystal Red Tetras. By selecting and pairing compatible breeding pairs based on size and color differences, hobbyists can increase the likelihood of successful breeding and production of healthy fry.

Observing these differences is also crucial for overall care and health of Crystal Red Tetras in the aquarium. By being aware of these physical distinctions, hobbyists can monitor the well-being of their fish and detect any potential health issues that may arise.

Reproduction

The Crystal Red Tetra is an egg-scattering free spawner and does not exhibit any parental care for their eggs or fry.

In a mature aquarium, adult Crystal Red Tetras will often spawn, and while it is possible for small numbers of fry to appear without intervention, a more controlled approach is recommended to maximize the yield of fry.

To accomplish this, a smaller aquarium should be set up and filled with mature water. The environment should be dimly lit, and the base should be covered with a mesh or fine-leaved plant. The water should be slightly acidic to neutral in pH, with a temperature towards the upper end of the suggested range.

When the adult fish are well-conditioned, a single pair or a group comprising one or two males and several females can be introduced to each container and left in place until eggs are detected, typically the following morning.

To ensure proper oxygenation and water movement, an air-powered sponge filter or air stone should be included in the breeding tank.

Initially, the fry should be fed Paramecium or a proprietary dry food of sufficiently small grade. As the fry grow larger, Artemia nauplii, microworms, and other suitable foods can be introduced.

By following a controlled approach to breeding, hobbyists can successfully breed and raise healthy Crystal Red Tetra fry.

Notes

Hyphessobrycon haraldschultzi, also known as Schultz’s Tetra or Araguaia Red, is a species that is occasionally available in the aquarium trade. This species is typically caught as bycatch among shipments of other fishes.

Hyphessobrycon haraldschultzi is a part of the Hyphessobrycon callistus species group as proposed by Géry in 1977. This group is characterized by a prominent dark spot on the dorsal-fin, usually with a white or yellow marking beneath. Members of this group are sometimes referred to collectively as ‘flag tetras’.

Hyphessobrycon haraldschultzi is distinguished by possession of a relatively small humeral spot and 5 or 5½/3-3½ transverse scales, and in these respects it could not be differentiated from H. eques. The two can be separated by various aspects of color pattern, however, most obviously that in the dorsal-fin. H. eques possesses a very large dark marking that covers most of the fin above the base, whereas in H. haraldschultzi a similarly-colored marking is less extensive and is bordered above by a white blotch and below by a yellowish band while the base of the dark marking is parallel to the body profile.

Weitzman & Palmer (1997) expanded Géry’s concept and proposed the existence of a putatively monophyletic assemblage based on color pattern and male fin morphology that they termed the ‘rosy tetra clade’. It was composed of species with the following shared characters which set them apart from other Hyphessobrycon species: pink to red or reddish-brown body color, 22-29 branched anal-fin rays, 29-34 longitudinal scales, and two sets of teeth on the premaxilla with 1-4 teeth in the outer series and 7-12 in the inner series.

Hyphessobrycon was initially raised by Durbin in Eigenmann (1908) as a subgenus of Hemigrammus, differing from the latter by the absence of scales on the caudal-fin. The grouping was revised by Eigenmann (1918, 1921) while Géry (1977) created artificial groups of species based on color pattern, and these definitions are still widely used today, e.g., the H. agulha group, the H. heterohabdus group, etc.

The process of splitting Hyphessobrycon up has already started. Malabarba et al. (2012) revalidated the genus Ectrepopterus Fowler, previously considered a synonym of Hyphessobrycon. They also analyzed its relationships within the Characidae in the context of Mirande’s (2010) previous work, but included the type species, H. compressus, for the first time in such a study. The results demonstrated that H. compressus is more closely-related to ‘rosy tetra’ representatives such as H. eques, H. pulchripinnis, and H. socolofi than other members of the genus including H. anisitsi, H. bifasciatus, H. elachys, H. herbertaxelrodi, and H. luetkeni.

References

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   Hyphessobrycon haraldschultzi new species.
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   Revalidation of the genus Ectrepopterus Fowler (Teleostei: Characiformes), with the redescription of its type species, E. uruguayensis.
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   A new species of Hyphessobrycon (Teleostei: Characidae) from the Neblina region of Venezuela and Brazil, with comments on the putative `rosy tetra clade’.
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