Hyphessobrycon pyrrhonotus BURGESS, 1993

Flame-back Bleeding Heart Tetra

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.

pyrrhonotus: from the Ancient Greek πυρρός (pyrrho), meaning ‘tawny, red’, and ‘, and νότος (notos), which is normally said to mean ‘back’ but also appears to signify ‘south’.

Classification

Order: Characiformes Family: Characidae

Distribution

Endemic to the rio Negro system in Amazonas state, Brazil, although the full extent of its range is unclear.

Type locality is ‘Rio Ereré, tributary to Rio Negro, Brazil’, and local fishermen apparently consider it restricted to the Ereré plus the rios Demeni and Aracá, all minor tributaries close to the town of Barcelos in the middle Negro.

The point where the rio Branco enters the Negro main channel thus appears to be the southern boundary of its range, with the rio Padauari representing its northern limit (Teixera, 2010).

See ‘Notes’ for further information concerning the distribution of H. pyrrhonotus and its relatives in the Amazon.

Habitat

The rio Ereré is a small river measuring just 7-12 metres in width and H. pyrrhonotus has been observed to swim in small groups among submerged woody structures such as roots, fallen branches, overhanging riparian vegetation or aquatic plants.

Substrates are typically composed of white sand with patches of leaf litter common and the fish display a preference for shallow (30-90 cm deep) zones.

The water has a negligible dissolved mineral content, is poorly buffered and stained brown due to the gradual release of tannins and organic acids from decaying plant material.

Sympatric species at one locality in the rio Ereré basin included  Hemigrammus ex gr. bellottii, Hemigrammus vorderwinkleri, Parapristella georgiae, Moenkhausia copei, Paracheirodon axelrodi, Copella nattereri, Nannostomus marginatus, Nannostomus trifasciatus, Ammocryptocharax elegans, Fluviphylax pygmaeus, Heros sp. and Apistogramma gibbiceps.

Maximum Standard Length

40 – 45 mm.

Aquarium SizeTop ↑

An aquarium with base dimensions of 75 ∗ 30 cm or equivalent should be the smallest considered.

Maintenance

Choice of décor is not especially critical, although this species tends to show better colouration when maintained in a well-furnished aquarium with live plants. A natural-looking arrangement might consist of a soft, sandy substrate with wood roots and branches placed such a way that plenty of shady spots are formed.

The addition of dried leaf litter would further emphasise the natural feel and with it the growth of beneficial microbe colonies as decomposition occurs. These can provide a valuable secondary food source for fry, whilst the tannins and other chemicals released by the decaying leaves are considered beneficial.

Like many fishes that naturally inhabit pristine environments it is intolerant to accumulation of organic pollutants and requires spotless water, meaning weekly water changes should be considered routine and it should never be introduced to a biologically immature aquarium.

Water Conditions

Temperature: 20 – 28 °C

pH: 4.0 – 7.0

Hardness: 18 – 143 ppm

Diet

This species is an opportunistic omnivore by nature. The stomach contents of wild specimens from the rio Ereré were composed of fruit remains, aquatic insects and larvae (Trichoptera, Heteroptera, Diptera and Ephemeroptera) and terrestrial ants (Hymenoptera; Formicidae). Fruit and ants constituted 25 % and 20 %, respectively, of all items consumed.

In the aquarium it is easily-fed but the best condition and colours offer regular meals of small live and frozen foods such as chironomid larvae (bloodworm), Daphnia, Artemia, etc., alongside good quality dried flakes and granules.

Submerged pieces of fresh fruit will also be grazed but should only be left in the aquarium for a few hours.

Behaviour and CompatibilityTop ↑

This species is generally peaceful making it an ideal resident of the well-researched community aquarium, although adult males are territorial to an extent, and this behaviour may sometimes extend to similarly-shaped species. It is perhaps best-maintained alongside similarly-sized characids, gasteropelecids, lebiasinids, smaller callichthyid or loricariid catfishes and non-predatory, medium-sized cichlids.

Try to buy a group of at least 8-10 specimens comprising both males and females, include other schooling fishes to provide security, and you will be rewarded with a more natural-looking spectacle. The interaction between rival males is fascinating to watch and they will display their best colours when competing for female attention or hierarchical position.

Sexual Dimorphism

Males grow noticeably larger and are more intensely-coloured than females.

In adult males the dorsal, pelvic and anal fins are highly extended, while adult females tend to be rounder in shape, especially when gravid.

Reproduction

Unrecorded but certain to be an egg-scatterer exhibiting no parental care.

NotesTop ↑

This is the smallest of three similar-looking species most commonly-referred to as the ‘bleeding heart’ subgroup, the other two being H. erythrostigma and H. socolofi.

All possess a reddish humeral spot which is not present in any other characid, with other shared characters including possession of 6 -14 maxillary teeth, 7-9 scales above the lateral line, 5-7 scales below the lateral line and 26-33 anal fin rays.

H. pyrrhonotus can be told apart from the other bleeding heart tetras quite easily since it uniquely possesses a red, wedge-shaped patch of red pigmentation in the upper part of the body, extending from below the dorsal-fin to the base of the caudal. This may be more apparent in well-conditioned or dominant individuals, sometimes reaching the head and snout in sexually mature males.

It is further distinguished from H. erythrostigma by lacking hook-like structures in the fins of mature males (vs. hooks present in the anal fins, dorsal and pelvic in mature males of H. erythrostigma), and from H. socolofi by the following combination of characters: 33-34 vertebrae, mode 33 (vs. 31-33, mode 32 in H. socolofi); a white longitudinal band extending distally along the majority of the anal-fin in adults, covering 70 to 95 % of the rays (vs. white band covering 45-50 % of the branched anal-fin rays only); first branched ray of anal-fin longest in adult males (vs. third branched ray); length of anal-fin in adult females 21.8-24.5 % SL, mean 23.52 % (vs. 18.01- 21.22 % SL, mean 19.37 %); no hook-like structures on fins (vs. numerous hooks on all fins except the adipose -fin in mature males and anal-fin in mature females); scales cycloid (vs. scales cyclo-ctenoid in mature males and some mature females).

H. pyrrhonotus also has the most restricted range among the bleeding heart group with H. erythrostigma relatively widespread in the upper Amazon region from the rio Purus, Brazil, at least as far upstream as the Río Nanay in Peru, and H. socolofi occurring throughout much of the rio Negro basin, including the rio Branco, plus the rio Nhamundá which enters the Amazon downstream of its confluence with the Negro.

Limited genetic analyses have revealed that the bleeding heart group is probably monophyletic, but that there may be more species involved (Paz et al., 2014). The current concept of H. socolofi appears to represent a paraphyletic taxon, for example, while H. pyrrhonotus also contains distinct lineages, although further work is necessary in order to deduce taxonomic implications.

In addition to forming their own putative assemblage the bleeding heart tetras have regularly been included in the larger ‘Hyphessobrycon bentosi‘ subgroup of the H. callistus group as proposed by Géry (1977). At the time of Géry’s work H. erthythrostigma was the only recognised bleeding heart tetra and he considered it to differ from other H. bentosi subgroup members by a combination of morphometric characters plus the red humeral spot.

Weitzman & Palmer (1997) expanded Géry’s concept and proposed the existence of a putatively monophyletic assemblage based on colour 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 colour; 22-29 branched anal-fin rays; 29-34 longitudinal scales; two sets of teeth on the premaxilla with 1-4 teeth in the outer series and 7-12 in the inner series.

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.

Like many small characids, H. pyrrhonotus is susceptible to an affliction which causes some or all of the body scales to appear metallic gold in colour. It remains unclear whether this is a consequence of a parasitic infestation, as has been suggested, but affected fish appear to be in no discomfort and their lifespan and overall health seem undiminished.

References

1. Burgess, W. E., 1993 - Tropical Fish Hobbyist 42(1): 156-160
   Hyphessobrycon pyrrhonotus, a new species of bleeding heart tetra (Teleostei: Characidae) from the Rio Erere, Brazil.
2. 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.
3. Géry, J., 1977 - T.F.H. Publications, Inc.: 1-672
   Characoids of the World.
4. Hein, G., 2009 - Bulletin of Fish Biology 10(1/2): 1-10
   Hyphessobrycon pando sp. n., a new rosy tetra from northern Bolivia (Teleostei, Characiformes, Characidae).
5. 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.
6. Mirande, J. M., 2010 - Neotropical Ichthyology 8(3): 385-568
   Phylogeny of the family Characidae (Teleostei: Characiformes): from characters to taxonomy.
7. 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.
8. Paz, F. P. C., J. D. S. Batista, and J. I. R. Porto, 2014 - PLoS One 9(5): e98603
   DNA Barcodes of Rosy Tetras and Allied Species (Characiformes: Characidae: Hyphessobrycon) from the Brazilian Amazon Basin.
9. 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.
10. Teixera, T. F., 2010 - PHD Thesis: i-xv + 1-144
    Revisão taxonômica das espécies de Hyphessobrycon Durbin do grupo rosacéo pingo-de-sangue (Ostariophysi; characiformes;. Characidae): comentários dobre a biologia reprodutiva do grupo.
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