Hyphessobrycon anisitsi
Buenos Aires Tetra
SynonymsTop ↑
Hemigrammus anisitsi Eigenmann, 1907; Hemigrammus caudovittatus Ahl, 1923; Hyphessobrycon erythrurus Ahl, 1928
Etymology
Hyphessobrycon: from the Ancient Greek υπελάσσων (hyphesson), meaning ‘of lesser stature’, and used as a prefix in this case, plus the generic name Brycon.
anisitsi: named for Professor J. D. Anisits of Asunción, Paraguay, who collected the type series.
Classification
Order: Characiformes Family: Characidae
Distribution
Widely-distributed throughout much of the Paraná river system in Brazil, Paraguay, and Argentina, plus the Uruguay watershed in Uruguay and Brazil.
Type locality is given simply as ‘Villa Rica, Paraguay’, this referring to the city of Villarrica in Guairá Department, central Paraguay, with some of the type series also deriving from Estancia la Armonia in President Hayes Department.
Some records from Buenos Aires province, Argentina are now considered to refer to the similar-looking congener H. togoi (Miquelarena and López, 2006) so the common vernacular name ‘Buenos Aires tetra’ may in fact be somewhat misleading.
Habitat
Occurs in smaller streams and tributaries more often than in major river channels and is also common in floodplain lakes, backwaters and oxbows.
In the Esteros del Iberá wetland reserve, Argentina, it occurs sympatrically with a number of other genus members including H. auca, H. elachys, H. eques, H. igneus, H. luetkeni, H. meridionalis, H. reticulatus and H. wajat.
All its natural waters lie in a subtropical region with abundant rainfall and relatively mild winters.
Maximum Standard Length
50 – 60 mm.
Aquarium SizeTop ↑
An aquarium with base dimensions of 90 ∗ 30 cm or equivalent should be the smallest considered.
Maintenance
Choice of décor is not especially critical though it tends to show better colouration in a well-structured, ideally planted, set-up.
Filtration does not need to be particularly strong though it does seem to appreciate a degree of water movement.
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
Probably a foraging omnivore feeding primarily on worms, insects and other zooplankton, as well as smaller amounts of plant material and organic detritus in nature.
In the aquarium it is easily-fed but the best condition and colours offer regular meals of small live and frozen foods such as bloodworm, Daphnia, and Artemia alongside good quality dried flakes and granules, at least some of which should include additional plant or algal content.
Behaviour and CompatibilityTop ↑
Has a reputation for nipping the fins of tankmates though this behaviour only tends to be pronounced when insufficient numbers are purchased or space is limited.
It is a gregarious species forming loose hierarchies, with rival males continually battling with each other for female attention and positioning within the group.
A group of at least 8-10 specimens should be considered the minimum requirement since this increases the likelihood that the fish will be distracted by each other rather than their tankmates but will result in a more effective, natural-looking display. Males will also show better colouration in the presence of conspecific rivals.
That said it is relatively boisterous and doesn not make an ideal companion for very shy, slow-moving, or long-finned fishes such as many livebearers, cichlids, and anabantoids.
Robust fishes inhabiting similar biotopes in nature, especially comparably-sized, open water-dwelling characids perhaps constitute the best choices but 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, but be sure to research your choices thoroughly before purchase.
Sexual Dimorphism
Sexually mature males are noticeably more intensely-coloured, slimmer-bodied and remain a little smaller than females.
Reproduction
An egg-scattering free spawner exhibiting no parental care.
When in good condition adults will spawn often and in a mature aquarium it’s possible that small numbers of fry may start to appear without intervention, but if you want to maximise yield a more controlled approach is required.
The adult group can still be conditioned together but a smaller aquarium should also be set up and filled with mature water. This should be very dimly lit and the base covered with some kind of mesh of a large enough grade so that the eggs can fall through but small enough so that the adults cannot reach them.
The widely available plastic ‘grass’-type matting can also be used and works well, as does a layer of glass marbles. Alternatively filling much of the tank with a fine-leaved plant such as Taxiphyllum spp. or spawning mops can also return decent results.
The water itself should be of slightly acidic to neutral pH with a temperature within the range suggested above. An air-powered sponge filter or air stone(s) should also be included to provide oxygenation and water movement.
When the adult fish are well-conditioned a single pair or group comprising one or two males and several females can then be introduced to each 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, these normally hatching in 24-36 hours at which point the fry still have a good-sized yolk sac attached.
Initial food should be Paramecium or a proprietary dry food of sufficiently small (5-50 micron) grade, introducing Artemia nauplii, microworm, etc., once the fry are large enough to accept them.
NotesTop ↑
This species is a popular and hardy aquarium subject and an albino (sometimes traded as ‘golden’) strain has been selectively line-bred for the hobby.
H. anisitsi looks very similar to the congener H. auca but can be told apart by possessing a single maxillary tooth with 3-5 cusps (vs. always 5 cusps in H. auca), dentary depth 50.0-53.3% of dentary length (vs. 40.7-47.6 %), and lacking small hooks on the dorsal, caudal and pectoral fins in males (vs. possessing small hooks on these fins in males).
Hyphessobrycon was 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 colour pattern, and these definitions are still widely used today, e.g., the H. agulha group, the H. heterohabdus group, etc. These cannot be considered to represent monophyletic assemblages, however, and their concepts continue to be redefined.
Weitzman & Palmer (1997) hypothesised the existence of a monophyletic assemblage within the genus based on colour pattern and male fin morphology that they termed the ‘rosy tetra clade’, with one of the characters supporting its monophyly being presence of a prominent dark marking on the dorsal-fin. This assemblage, plus other morphologically similar species, is considered to represent Hyphessobrycon sensu stricto by some authors, with the remaining species included in a much-expanded H. heterohabdus group.
Others have proposed conflicting, typically more restricted, views of both the genus and/or its constituent species groups, and significant confusion remains. What is clear is that, as currently recognised, Hyphessobrycon is a polyphyletic lineage containing several genera.
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 analysed 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
- 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. - 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. - 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. - 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. - Géry, J., 1977 - T. F. H. Publications, Inc.: 1-672
Characoids of the world. - 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. - 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. - Mirande, J. M., 2010 - Neotropical Ichthyology 8(3): 385-568
Phylogeny of the family Characidae (Teleostei: Characiformes): from characters to taxonomy. - 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. - 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. - 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'. - Zarske, A., 2014 - Vertebrate Zoology 64(2): 139-167
Zur Systematik einiger Blutsalmler oder "Rosy Tetras" (Teleostei: Ostariophysi: Characidae).
