Orangefin tetra

Orangefin tetra
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Iguanodectidae
Genus: Bryconops
Species:
B. affinis
Binomial name
Bryconops affinis
Günther, 1864

The orangefin tetra (Bryconops affinis)[1][2] is a small species of freshwater fish from South America that belongs to the family Iguanodectidae. Though common in its native range, it seems to prefer fast-flowing and shallow creeks. It is an active swimmer that feeds on plant material and various invertebrates, sometimes jumping out of the water to catch prey above the surface.

It has a peaceful demeanor, living in schools and inhabiting the same areas as various other fish species. When it spawns, it prefers environments with plentiful vegetation. Its eggs are adhesive, and are released in batches instead of all at once.

It looks quite similar to one of its congeners, B. melanurus, hence the specific epithet "affinis" (which means "close to"). Another common name is "orangefin characin", but this is inaccurate; a characin is any fish of the family Characidae, and the orangefin tetra belongs to the family Iguanodectidae. However, it used to be classified as a member of Characidae, so the name is not outright incorrect, just outdated.

Description

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The orangefin tetra is relatively small, reaching a maximum of 12.0 cm (4.7 in) in total length;[3] this makes it similar in size to its congeners B. caudomaculatus and B. cyrtogaster.[4] The body shape is generally reminiscent of all Bryconops species, described as "smelt-like", similar to the genus Piabucus.[5] Upon close inspection, the scales of B. affinis display very faint radial lines, where the rest of the genus has stronger scale patterning.[6]

The common name "orangefin tetra" originates from the spots of bright orange on the caudal fin on both the upper and lower lobes.[7] Its dorsal fin is also orange, but this is not as evident upon first glance, and is more pronounced in some specimens than others. The scientific name "affinis" means "close to" in Latin, which is an indicator of similarity to its congener B. melanurus.[8]

Taxonomy

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The baisonym of Bryconops affinis is Tetragonopterus affinis, given by Albert Günther in 1864.[9] It has also been referred to as Creatochanes affinis and Roeboides affinis,[10][11] though the latter of these is now used for a different species altogether.[12] The former name, however, still holds some accuracy; Creatochanes technically stands as a subgenus of Bryconops, to which B. affinis belongs (alongside B. caudomaculatus and B. melanurus).[13]

This is a vintage photograph of five fish. The first in line is somewhat football-shaped and has a dark spot on its dorsal fin. The second is shaped similarly to the first, but has a dark spot on its tail fin. The third is more elongate than the first two, and has a dusky tail fin. The fourth is similar in shape to the third, and has a dark stripe on its tail fin that veers upwards from the center. The fifth is similar in shape to the fourth and third, and has a distinct bright spot on the upper lobe of its tail fin.
Bryconops affinis is the center fish in this photograph. At the time, it was called Creatochanes affinis.

When first described by Rudolf Kner, the genus Bryconops was classified as a member of the family Characidae, which is  an extraordinarily variable family of fishes.[14] However, research from Oliveira et al. in 2011 prompted Bryconops, along with Piabucus and Iguanodectes, to be moved to the family Iguanodectidae, which was revived from the work of ichthyologist Carl H. Eigenmann.[15][16] Another common name for the orangefin tetra is "orangefin characin", but this is outdated due to the 2011 move, as a characin is any member of Characidae.[17]

Habitat and ecology

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Upon describing the species, Günther defined the type locality as Guyana.[18] It is also known from Paraguay, the Amazon, and Rio San Francisco.[19] Furthermore, its range includes the Mamore, Guapore, Tocantins, and Trombetas rivers.[20] Ichthyologist John D. Haseman attributed B. affinis' wide distribution to the fact that it has a more generalist nature than its congeners.[21] It has been mistakenly cited as appearing in Venezuela, but this is not the case.[22] Outside of its native range, it has been added to the Victorian Fisheries Authority's list of noxious aquatic species.[23]

The orangefin tetra is relatively placid, living in the same areas as various other fish species without dispute.[24] It has a known preference for water with a moderate or strong current, where it stays near the surface.[25] Its preference extends to areas with plentiful vegetation, which makes up part of its diet; it also feeds on various invertebrates.[3] While not an active part of the fish market in its native range, it serves as a food source for fishes that are.[26] It is also subject to infestations by gill parasites of the genus Jainus (not to be confused with the sawfly genus Janus).[27][28]

The orangefin tetra is a batch spawner, releasing batches of eggs over a period of time as opposed to all at once.[29] The eggs adhere to the substrate where they are placed, and this is thought to be a result of structural aspects of the egg (as opposed to an additional substance secreted upon being laid).[30][31] The zona pediculla, one of the outer layers of the egg, displays structural specializations during formation that likely play a role.[32]

Conservation status

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The orangefin tetra is of interest to hobbyists, but it has not been evaluated by the International Union for the Conservation of Nature (IUCN);[3][33] however, a wide distribution and hardy nature make an endangered status unlikely. Nonetheless, it is known to be exported from Guyana for use in the aquarium industry.[34] Data for less popular species, like B. affinis, is low.[35]

References

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  1. ^ "Animal Diversity Web: Bryconops affinis Classification". Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 5 March 2022.
  2. ^ "NCBI Taxonomy Browser (Bryconops affinis)". NCBI Taxonomy Browser. National Center for Biotechnology Information. Retrieved 5 March 2022.
  3. ^ a b c Froese, Rainer; Pauly, Daniel (eds.). "Bryconops affinis". FishBase. March 2022 version.
  4. ^ Froese, Rainer; Pauly, Daniel (eds.). "Species in genus Bryconops". FishBase. March 2022 version.
  5. ^ van der Sleen, Peter; Albert, James S. (2018). "THE FISH FAMILIES". Field Guide to the Fishes of the Amazon, Orinoco, and Guianas. Princeton University Press. pp. 69–402. doi:10.1515/9781400888801-009. ISBN 9781400888801. S2CID 188010661.
  6. ^ Cockerell, Theodore D. A. (September 1914). "The scales of the South American Characinid fishes". Annals of the Carnegie Museum. 9 (1–2): 103. doi:10.5962/p.331043. S2CID 251481912. Retrieved 5 March 2022.
  7. ^ Chernoff, Barry; Machado-Allison, Antonio (2005-12-31). "Bryconops". doi:10.5281/zenodo.6265593. {{cite journal}}: Cite journal requires |journal= (help)
  8. ^ Scharpf, Christopher; Lazara, Kenneth J. (15 September 2020). "Order CHARACIFORMES: Families IGUANODECTIDAE, TRIPORTHEIDAE, BRYCONIDAE, CHALCEIDAE and GASTEROPELECIDAE". The ETYFish Project. Retrieved 5 March 2022.
  9. ^ Bryconops affinis (Günther, 1864) in GBIF Secretariat (2021). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2022-03-05.
  10. ^ Rees, Tony (31 December 2011). "IRMNG - Bryconops affinis (Günther, 1864)". International Register of Marine and Nonmarine Genera. Retrieved 4 March 2022.
  11. ^ "Taxonomy - Bryconops affinis (orangefin tetra)". UniProt. Retrieved 5 March 2022.
  12. ^ Froese, Rainer; Pauly, Daniel (eds.). "Roeboides affinis". FishBase. March 2022 version.
  13. ^ Chernoff, Barry; Machado-Allison, Antonio (13 December 2005). "Bryconops magoi and Bryconops collettei (Characiformes: Characidae), two new freshwater fish species from Venezuela, with comments on B. caudomaculatus (Günther)". Zootaxa. 1094 (1): 23. doi:10.11646/zootaxa.1094.1.1. ISSN 1175-5334 – via Biotaxa.
  14. ^ Kner, Rudolf (1858). "Beiträge zur Familie der Characinen". Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften (in German). 30: 80 – via Biodiversity Heritage Library.
  15. ^ Oliveira, Claudio; Avelino, Gleisy S.; Abe, Kelly T.; Mariguela, Tatiane C.; Benine, Ricardo C.; Ortí, Guillermo; Vari, Richard P.; Corrêa e Castro, Ricardo M. (December 2011). "Phylogenetic relationships within the speciose family Characidae (Teleostei: Ostariophysi: Characiformes) based on multilocus analysis and extensive ingroup sampling" (PDF). BMC Evolutionary Biology. 11 (1): 275. doi:10.1186/1471-2148-11-275. ISSN 1471-2148. PMC 3190395. PMID 21943181.
  16. ^ Froese, Rainer; Pauly, Daniel (eds.). "Family Iguanodectidae". FishBase. March 2022 version.
  17. ^ "Orangefin Characin Bryconops affinis (Günther 1864)". Encyclopedia of Life. Retrieved 5 March 2022.
  18. ^ Wingert, Juliana Mariani (2010). Descrição de duas novas espécies de Bryconops (Teleostei: Characidae) da bacia do rio Amazonas, Porto Alegre: Universidade Federal do Rio Grande do Sul.
  19. ^ Eigenmann, Carl H.; Meyers, George S. (1917–1929). The American Characidae. Cambridge. pp. 493–499. Retrieved 5 March 2022.
  20. ^ Dagosta, Fernando C. P.; Pinna, Mário De (June 2019). "The Fishes of the Amazon: Distribution and Biogeographical Patterns, with a Comprehensive List of Species". Bulletin of the American Museum of Natural History. 2019 (431): 1–163. doi:10.1206/0003-0090.431.1.1. S2CID 196645665.
  21. ^ Haseman, John D. (31 May 1912). "Some factors of geographical distribution in South America". Annals of the New York Academy of Sciences. 22 (1). New York: New York Academy of Sciences: 59. Bibcode:1912NYASA..22....9H. doi:10.1111/j.1749-6632.1912.tb55158.x. hdl:2027/chi.14414574. ISSN 0077-8923. OCLC 1306678. S2CID 129708724. Retrieved 5 March 2022.
  22. ^ Machado-Allison, Antonio; Buckup, Paulo; Chernoff, Barry; Royero, Ramiro (March 1993). "Las especies del genero Bryconops Kner, 1858 en Venezuela (Teleostei, Characiformes)". Acta Biologica Venezuelica. 14 (3): 1–20.
  23. ^ "Noxious Aquatic Species in Victoria". Victorian Fisheries Authority. 8 July 2010. Retrieved 5 March 2022.
  24. ^ de Pinna, Mário C. C.; Keith, Philippe (2003). "A new species of the catfish genus Ituglanis from French Guyana (Osteichthyes: Siluriformes: Trichomycteridae)". Proceedings of the Biological Society of Washington. 116: 878 – via Biodiversity Heritage Library.
  25. ^ Mol, Jan H.A. (2012). The Freshwater Fishes of Suriname. BRILL. p. 240. ISBN 9789004207660.
  26. ^ Feitosa, Pfp; Ribeiro, Vs; Rocha, Aaf; Silva, Alb; Nascimento, Grs; Nicola, P (2016). Avaliação comparativa da dieta da espécie Bryconops aff. affinis (Günther, 1864) em dois trechos no Rio São Francisco (Comparative evaluation of the diet of the species Bryconops aff. affinis (Günther, 1864) in two sections in the São Francisco Rivers). Cemafauna Caatinga.
  27. ^ Braga, Mariana P.; Razzolini, Emanuel; Boeger, Walter A. (5 October 2014). "Drivers of parasite sharing among Neotropical freshwater fishes". Journal of Animal Ecology. 84 (2): 487–497. doi:10.1111/1365-2656.12298. ISSN 0021-8790. PMID 25283218 – via Ecological British Society.
  28. ^ "Jainus". Encyclopedia of Life. Retrieved 5 March 2022.
  29. ^ Bazzoli, Nilo; Enemir, José; Dos Santos, José; Diniz, Marcelo; de Barros, M. (June 2013). "Biologia reprodutiva do Bryconops cf. affinis = Creatochanes affinis (Gunther, 1864) (Teleostei: Characiformes) na lagoa do Pantaninho, Lagoa da Prata, Minas Gerais". BIOS. 5 (5): 43–51. eISSN 0366-2284.
  30. ^ Rizzo, E.; Sato, Y.; Barreto, B. P.; Godinho, Hugo P. (September 2002). "Adhesiveness and surface patterns of eggs in neotropical freshwater teleosts". Journal of Fish Biology. 61 (3): 615–632. Bibcode:2002JFBio..61..615R. doi:10.1111/j.1095-8649.2002.tb00900.x.
  31. ^ Weber, André Alberto; Arantes, Fábio Pereira; Sato, Yoshimi; Rizzo, Elizete; Bazzoli, Nilo (May 2013). "Oocyte adhesiveness and embryonic development of Astyanax bimaculatus (Linnaeus, 1758) (Pisces: Characidae)". Zygote. 21 (2): 198–202. doi:10.1017/S096719941200007X. PMID 22717095. S2CID 22097917. ProQuest 1430897277.
  32. ^ Andrade, R. F.; Bazzoli, N.; Rizzo, E.; Sato, Y. (October 2001). "Continuous gametogenesis in the neotropical freshwater teleost, Bryconops affinis (Pisces:Characidae)". Tissue & Cell. 33 (5): 524–532. doi:10.1054/tice.2001.0206. PMID 11949788.
  33. ^ A Strategic approach to the management of ornamental fish in Australia : communication strategy and grey list review, a report to OFMIG (PDF). Andy Moore. Canberra, A.C.T.: Bureau of Rural Sciences. 2010. ISBN 978-1-921192-37-1. OCLC 604914255.{{cite book}}: CS1 maint: others (link)
  34. ^ Prang, Gregory (2008). "An industry analysis of the freshwater ornamental fishery with particular reference to the supply of Brazilian freshwater ornamentals to the UK market". Uakari. 3: 7–57. doi:10.31420/uakari.v3i1.18.
  35. ^ Ouboter, P.E. (2012). The Freshwater Ecosystems of Suriname. Springer Science & Business Media. p. 145. ISBN 9789401120708. Retrieved 5 March 2022.
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