Hyphessobrycon anisitsi (EIGENMANN, 1907) Buenos Aires Tetra

Synonyms

Hemigrammus anisitsi Eigenmann, 1907;

Hemigrammus caudovittatus Ahl, 1923;

Hyphessobrycon erythrurus Ahl, 1928

Etymology

Hyphessobrycon is a genus of fish whose name originates from the Ancient Greek word “υπελάσσων” (hyphesson), meaning ‘of lesser stature,’ used as a prefix in this case, in combination with the generic name Brycon. The name refers to the small size of the fish compared to other species within the same family.

Another example is Hyphessobrycon anisitsi, which is named in honor of Professor J. D. Anisits from Asunción, Paraguay, who collected the type series of this particular species. The discovery and collection of the type series played a crucial role in the scientific classification and identification of this fish species.

Overall, the naming of fish species is an important aspect of their classification and recognition. It often reflects the characteristics or significance of the species and acknowledges the contributions of individuals who have played a role in their discovery and study.

Classification

Here is the taxonomic classification of Hyphessobrycon anisitsi:

• Kingdom: Animalia
• Phylum: Chordata
• Class: Actinopterygii
• Order: Characiformes
• Family: Characidae
• Genus: Hyphessobrycon
• Species: Hyphessobrycon anisitsi

So the complete scientific name of the bloodfin tetra is Hyphessobrycon anisitsi.

Distribution

The species under discussion is widely distributed throughout much of the Paraná river system in Brazil, Paraguay, and Argentina, as well as the Uruguay watershed in Uruguay and Brazil. Its type locality is given simply as ‘Villa Rica, Paraguay’, which refers to the city of Villarrica in Guairá Department, central Paraguay. Some of the type series also derive from Estancia la Armonia in President Hayes Department.

It is important to note that some records from Buenos Aires province in Argentina are now considered to refer to the similar-looking congener H. togoi, as reported by Miquelarena and López in 2006. Therefore, the common vernacular name ‘Buenos Aires tetra’ may be somewhat misleading, as it could refer to either species. This highlights the importance of accurate species identification and classification, which can have implications for ecological and conservation studies.

In summary, the distribution and type locality of this species, as well as its similarities with a congener, are important considerations in understanding its taxonomy and distribution. Such information can aid in the conservation and management of these fish populations and their habitats.

Habitat

This particular species of fish is more frequently found in smaller streams and tributaries, as opposed to major river channels, and is also commonly found in floodplain lakes, backwaters, and oxbows. In addition to its distribution in these types of aquatic environments, it is also found in the Esteros del Iberá wetland reserve in Argentina, where it coexists with several other members of its genus, including H. auca, H. elachys, H. eques, H. igneus, H. luetkeni, H. meridionalis, H. reticulatus, and H. wajat.

All of the natural waters where this species occurs are located in a subtropical region with abundant rainfall and relatively mild winters. The subtropical climate and varied aquatic environments likely contribute to the species’ widespread distribution in the region.

Understanding the natural habitats and environmental conditions in which a species occurs is important for effective conservation and management. This information can help inform strategies to protect and preserve the species and its habitat, as well as inform decisions about where and how to best allocate conservation resources.

Maximum Standard Length

50 – 60 mm.

Hyphessobrycon anisitsi, commonly known as the bloodfin tetra, is a small freshwater fish species that belongs to the Characidae family. It is native to South America, specifically found in the Paraguay and Paraná river basins. The maximum standard length of Hyphessobrycon anisitsi is reported to be approximately 5 centimeters (2 inches). This measurement is taken from the tip of the snout to the base of the tail fin, excluding the length of the tail fin itself.

It’s important to note that while the maximum reported standard length is around 5 centimeters, individual fish may vary in size due to various factors such as genetics, diet, and environmental conditions. In aquariums, bloodfin tetras may grow slightly smaller than their wild counterparts due to limited space and resources. However, with proper care and nutrition, they can reach their full potential size.

The bloodfin tetra is known for its distinctively colored fins. The dorsal fin and anal fin are a deep red color, which gradually fades to a clear, translucent color towards the tip. The body of the fish is silver in color, and it has a dark spot at the base of its tail fin.

Bloodfin tetras are generally peaceful and social fish, making them a popular choice for community aquariums. They thrive in schools of six or more, and prefer to be kept in a well-planted aquarium with plenty of hiding spots. They are also relatively easy to care for, making them a great choice for beginner fish keepers.

Aquarium Size

If you are considering keeping this particular species of fish in an aquarium, it is recommended that the tank have a base dimension of at least 90 x 30 cm, or an equivalent area. This ensures that the fish have adequate space to swim and move around comfortably.

To maintain a healthy environment for the fish, it is also advised to find a filter with a water flow that is between 4 to 5 times the volume of your aquarium. For an aquarium with a volume of 81 liters, we recommend a filter that can be found at this link. It is important to select a filter that is appropriate for the size of your aquarium to ensure that the water is properly filtered and circulated.

In addition to the recommended filter, you can also find other aquarium filters that have been highly recommended by customers in your area at this link. It is always helpful to read reviews and seek recommendations from other experienced hobbyists to ensure that you are selecting the best equipment for your aquarium setup.

Overall, providing an appropriate environment for your fish is crucial for their health and well-being. Selecting an appropriate filter and ensuring that the aquarium has adequate space are important factors to consider when setting up a tank for this species.

Maintenance

When it comes to choosing décor for an aquarium housing this species of fish, it is not particularly critical. However, the fish tend to display better coloration in a well-structured and ideally planted aquarium setup. Adding plants and other decor elements to the tank can also provide hiding places and territories for the fish, which can promote their overall health and well-being.

Regarding filtration, it is not necessary to have an especially strong filter. However, the species does seem to appreciate a degree of water movement. This can be achieved with a filter that provides gentle but consistent water circulation throughout the tank. Adequate water movement helps maintain good water quality by ensuring that debris and waste are properly circulated through the filter and removed from the tank.

In summary, while the choice of décor is not a critical factor in keeping this species of fish, a well-structured and ideally planted aquarium setup can enhance the fish’s coloration and provide a more natural and stimulating environment. Additionally, providing a degree of water movement through the use of an appropriately sized filter can further promote the health and well-being of the fish by maintaining good water quality.

Water Conditions

Temperature: 16 – 28 °C; it should not be maintained at temperatures towards the upper end of this range for extended periods (see ‘Habitat’).

pH: 5.5 – 8.5

Hardness: 18 – 357 ppm

Diet

This particular species of fish is most likely a foraging omnivore in the wild, feeding primarily on worms, insects, and other zooplankton. It may also consume smaller amounts of plant material and organic detritus as part of its diet. This varied diet allows the fish to obtain all the necessary nutrients and energy to thrive in its natural environment.

In the aquarium, this species is generally considered to be easy to feed. However, to maintain the best condition and coloration, it is recommended to offer regular meals of small live and frozen foods such as bloodworms, Daphnia, and Artemia. These types of foods provide a more natural and varied diet for the fish, which can promote their overall health and well-being.

In addition to live and frozen foods, it is also important to provide good quality dried flakes and granules in the fish’s diet. At least some of these should include additional plant or algal content to ensure that the fish is receiving a balanced and varied diet. A high-quality diet is important for promoting the fish’s overall health, immune system, and coloration.

In summary, this species is most likely a foraging omnivore in the wild, feeding on a variety of foods such as worms, insects, zooplankton, plant material, and detritus. In the aquarium, it is recommended to provide a varied diet consisting of live and frozen foods, as well as high-quality dried flakes and granules that include additional plant or algal content. This will ensure that the fish is receiving all the necessary nutrients to maintain optimal health, coloration, and overall well-being.

Behaviour and Compatibility

This species has a reputation for nipping the fins of other tankmates, though this behavior tends to be more pronounced when there are insufficient numbers of the species or when space is limited. It is a gregarious species that forms loose hierarchies, with rival males continually competing for female attention and positioning within the group.

To mitigate the nipping behavior and promote a more natural-looking display, it is recommended to keep a group of at least 8-10 specimens. This increases the likelihood that the fish will be distracted by each other rather than their tankmates. In addition, males will exhibit better coloration in the presence of conspecific rivals.

However, it is important to note that this species is relatively boisterous and does not make an ideal companion for very shy, slow-moving, or long-finned fishes such as many livebearers, cichlids, and anabantoids. Instead, robust fishes inhabiting similar biotopes in nature, especially comparably-sized, open water-dwelling characids, may be the best choices. Other potential options include callichthyid, loricariid, and doradid catfishes or benthic anostomids and curimatids from genera such as Schizothorax and Characidium.

If geography is not an issue, many rainbowfishes and cyprinids are also suitable tankmates. However, it is important to research your choices thoroughly before making any purchases to ensure that the fish will be compatible with each other in terms of behavior, diet, and water parameters.

In summary, while this species may nip the fins of other tankmates, keeping a group of 8-10 specimens can help mitigate this behavior. It is important to select tankmates that are robust and can tolerate the active and boisterous nature of this species. Researching potential tankmates thoroughly is key to ensuring a harmonious and healthy aquarium environment.

Sexual Dimorphism

Sexual dimorphism is present in this species, with mature males exhibiting more intense coloration, slimmer body shape, and smaller size compared to females.

Mature males can be easily distinguished from females by their noticeably more vibrant and striking coloration, which is typically more vivid and intense than that of females. In addition, mature males tend to have a slimmer body shape and are slightly smaller in size than females.

This sexual dimorphism is a natural adaptation that likely helps males attract females and defend their territory from other males. It is also an important consideration for aquarists when selecting and maintaining a breeding group of this species. By carefully selecting individuals of both sexes based on their size and coloration, aquarists can increase the likelihood of successful breeding and the production of healthy offspring.

Overall, understanding sexual dimorphism is an important aspect of maintaining and breeding this species. By carefully observing and selecting individuals based on their sex-specific traits, aquarists can ensure a healthy and harmonious aquarium environment.

Reproduction

This species is an egg-scattering free spawner that exhibits no parental care for its offspring. When in good condition, adult fish will spawn often, and in a mature aquarium, small numbers of fry may start to appear without intervention. However, to maximize the yield of fry, a more controlled approach is required.

To facilitate breeding, a smaller aquarium should be set up and filled with mature water. The base of the aquarium should be covered with mesh of a large enough grade so that the eggs can fall through but small enough so that the adults cannot reach them. Alternatively, plastic grass-type matting or a layer of glass marbles can be used. Spawning mops or fine-leaved plants such as Taxiphyllum spp. can also be effective.

The water in the breeding aquarium should be slightly acidic to neutral in pH, with a temperature within the range suggested for this species. An air-powered sponge filter or air stone should be included to provide oxygenation and water movement.

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 breeding container and left in place until eggs are detected, typically the following morning. Spawning normally occurs for 2-4 hours, and a well-conditioned mature female may lay as many as 2000 eggs during this period. The eggs will normally hatch in 24-36 hours, at which point the fry still have a good-sized yolk sac attached.

The initial food for the fry should be Paramecium or a proprietary dry food of sufficiently small grade, typically 5-50 microns. Once the fry are large enough to accept them, Artemia nauplii, microworms, and other live or frozen foods can be introduced.

In summary, breeding this species requires a controlled approach in a separate breeding aquarium. Providing appropriate substrate, water conditions, and food for the fry is important to ensure successful breeding and the production of healthy offspring.

Notes

Hyphessobrycon anisitsi is a popular and hardy species commonly kept in aquariums. In the aquarium hobby, an albino strain of this species, sometimes traded as ‘golden,’ has been selectively line-bred.

Hyphessobrycon anisitsi can be identified by its possession of a single maxillary tooth with 3-5 cusps, dentary depth 50.0-53.3% of dentary length, and the lack of small hooks on the dorsal, caudal, and pectoral fins in males. This distinguishes it from the similar-looking congener, H. auca, which always possesses 5 cusps on its single maxillary tooth, has dentary depth 40.7-47.6% of dentary length, and has small hooks on the dorsal, caudal, and pectoral fins in males.

Hyphessobrycon was originally raised as a subgenus of Hemigrammus by Durbin in Eigenmann (1908), with the main difference being the absence of scales on the caudal fin. The grouping was revised by Eigenmann (1918, 1921), and later Géry (1977) created artificial groups of species based on color pattern. These groups, such as the H. agulha group and H. heterohabdus group, are still widely used today. However, they do not represent monophyletic assemblages and their concepts continue to be redefined.

Weitzman & Palmer (1997) proposed the existence of a monophyletic assemblage within the genus based on color pattern and male fin morphology that they termed the “rosy tetra clade,” with one of the supporting characters being the presence of a prominent dark marking on the dorsal fin. Some authors consider this assemblage, plus other morphologically similar species, to represent Hyphessobrycon sensu stricto, with the remaining species included in an expanded H. heterohabdus group.

However, there are conflicting views on the genus and/or its constituent species groups, and significant confusion remains. It is clear that, as currently recognized, Hyphessobrycon is a polyphyletic lineage containing several genera. To address this, the process of splitting it up has already started, and 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, including the type species, H. compressus, for the first time in such a study. The results showed that H. compressus is more closely related to representatives of the “rosy tetra” clade 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

1. Eigenmann, C. H. and F. Ogle, 1907 – Proceedings of the United States National Museum v. 33 (no. 1556): 1-36
   An annotated list of characin fishes in the United States National Museum and the Museum of Indiana University, with descriptions of new species.
2. Almirón, A. E., J. R. Casciotta and S. Körber, 2006 – Revue Suisse de Zoologie 113(4): 889-896
   A new species of Hyphessobrycon (Characiformes, Characidae) from the río Uruguay basin, Argentina.
3. Almirón, A. E., J. R. Casciotta, J. A. Bechara and F. J. Ruíz Díaz, 2004 – Revue Suisse de Zoologie 111(3): 673-682
   A new species of Hyphessobrycon (Characiformes, Characidae) from the Esteros del Iberá wetlands, Argentina.
4. Calcagnotto, D., S. A. Schaefer, and R. DeSalle, 2005 – Molecular Phylogenetics and Evolution 36(1): 135-153
   Relationships among characiform fishes inferred from analysis of nuclear and mitochondrial gene sequences.
5. Géry, J., 1977 – T. F. H. Publications, Inc.: 1-672
   Characoids of the world.
6. Malabarba, L. R., V. A. Bertaco, F. R. Carvalho & T. O. Litz., 2012 – Zootaxa 3204: 47-60
   Revalidation of the genus Ectrepopterus Fowler (Teleostei: Characiformes), with the redescription of its type species, E. uruguayensis.
7. Miquelarena, A. M. and H. L. López, 2006 – Revue Suisse de Zoologie 113(4): 817-828
   Hyphessobrycon togoi, a new species from the La Plata basin (Teleostei: Characidae) and comments about the distribution of the genus in Argentina.
8. Mirande, J. M., 2010 – Neotropical Ichthyology 8(3): 385-568
   Phylogeny of the family Characidae (Teleostei: Characiformes): from characters to taxonomy.
9. Oliveira, C. A., G. S. Avellino, K. T. Abe, T. C. Mariguela, R. C. Benine, G. Orti, R. P. Vari, and R. M. Corrêa e Castro, 2011 – BMC Evolutionary Biology 11(1): 275-300
   Phylogenetic relationships within the speciose family Characidae (Teleostei: Ostariophysi: Characiformes) based on multilocus analysis and extensive ingroup sampling.
10. Reis, R. E., S. O. Kullander and C. J. Ferraris, Jr. (eds), 2003 – EDIPUCRS, Porto Alegre: i-xi + 1-729
    Check list of the freshwater fishes of South and Central America. CLOFFSCA.
11. Weitzman, S. H. and L. Palmer, 1997 – Ichthyological Exploration of Freshwaters 7(3): 209-242
    A new species of Hyphessobrycon (Teleostei: Characidae) from the Neblina region of Venezuela and Brazil, with comments on the putative `rosy tetra clade’.
12. Zarske, A., 2014 – Vertebrate Zoology 64(2): 139-167
    Zur Systematik einiger Blutsalmler oder “Rosy Tetras” (Teleostei: Ostariophysi: Characidae).