Bryconops melanurus

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Bryconops melanurus
1912 illustration
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Iguanodectidae
Genus: Bryconops
Species:
B. melanurus
Binomial name
Bryconops melanurus
(Bloch, 1794)

Bryconops melanurus, sometimes called the tail-light tetra, is a small species of freshwater fish from South America that primarily preys on insects. It lives in small schools and is an active swimmer, which means that it requires open space in its habitat. Nonetheless, it does not demonstrate a strong preference for any one biotope within its native range.

Description[edit]

Bryconops melanurus reaches a maximum total length of about 13.2 cm (5.2 in),[1] which puts it on the larger side of the genus Bryconops.[2] The head is slender, with a pointed snout, and B. melanurus lacks a humeral spot of the kind frequently seen in congeners (such as B. humeralis and B. inpai).[3] B. melanurus shares aspects of its jaw structure, which is rather lengthened, with B. inpai, B. affinis, and B. giacopinii.[4] (This was used to place giacopinii in the genus Bryconops instead of its originally described Autanichthys.)[4]

Bryconops melanurus is a silvery, slender fish with a darker back.[5] The caudal fin has distinctive markings, but lacks a well-formed ocellus (eyespot). There is a dark stripe about the width of the pupil that veers from the center of this fin up towards the dorsal lobe, and the caudal-fin margins are dusky.[6] The rest of the fin is either light in pigment (usually yellowish)[5] or entirely clear.[7]

Bryconops melanurus has noted morphological similarities with congeners B. transitoria and B. gracilis, but can be differentiated based on morphometric specifics and differences in fin structure; for instance, B. transitoria has 23-27 anal-fin rays, whereas B. melanurus has 28–29.[8] B. melanurus is also known to be similar to B. cytogaster, but cyrtogaster has a deeper body and a greater number of anal-fin rays (30-31).[9]

While it lacks a common name accepted by the wider scientific community,[10] hobbyists know it as the tail-light tetra.[11][12][13] It should not be confused with the head-and-tail light tetra, Hemigrammus ocellifer, which is a different fish in the same order, Characiformes.

Taxonomy[edit]

1797 illustration, labeled Salmo melanurus

Bryconops melanurus, when originally described by German naturalist Marcus Elieser Bloch in 1794, was named Salmo melanurus, and was listed as a salmon native to Suriname.[5][14] (In modern taxonomy, the name Salmo applies to a genus in the family Salmonidae that encompasses trout and salmon from Europe. B. melanurus is not native to Europe, nor is it a salmon.)

By 1926, it had been moved to the genus Creatochanes, which is reflected in a paper by English ichthyologist John Roxborough Norman.[9] Creatochanes is no longer considered a standalone genus, and is instead a subgenus of Bryconops to which B. melanurus belongs.[8] (This makes its full name Bryconops (Creatochanes) melanurus.)

DNA barcoding has revealed that B. melanurus is most closely related to B. transitoria and B. caudomaculatus, moreso the former than the latter.[15]

Habitat and ecology[edit]

The type locality of B. melanurus is Suriname, but no specific river was given in the original description.[5] Specimens have been cited from the Caraipé, Curuá, Madeira, and Moju rivers in modern accounts,[8] as well as the Tapajós.[15] Within this range, it seems to demonstrate no preference for any one biotope in particular, but does prefer living in groups.[1]

Diet[edit]

Bryconops melanurus feeds primarily on insects.[1] This is in line with the rest of the genus, members of which are largely invertivores, with a few noted herbivores on the list.[16] Specific dietary habits are unclear, but may be similar to habits of congeners B. inpai and B. magoi, which feed on terrestrial insects that are either washed into the river or that fall from trees hanging above.[17][18]

Conservation status[edit]

Bryconops melanurus has not been evaluated by the IUCN.[1] While it is known to be exported from Peru for use in the aquatics industry,[19] and it has a presence in hobbyist communities,[12] it is not thought to be endangered. Aquarists know it not to fare particularly well in tank settings, partially because it is an active swimmer that needs plenty of space.[1]

References[edit]

  1. ^ a b c d e Froese, Rainer; Pauly, Daniel (eds.) (2022). "Bryconops melanurus" in FishBase. October 2022 version.
  2. ^ Froese, Rainer and Pauly, Daniel, eds. (2022). Species of Bryconops in FishBase. October 2022 version.
  3. ^ Knöppel, Hans-armin; Junk, Wolfgang; Géry, Jacques (January 1968). "Bryconops (Creatochanes) Inpai, A New Characoid Fish From The Central Amazon Region, With A Review Of The Genus Bryconops". Amazoniana. 1 (3): 231–246. Retrieved 20 October 2022.
  4. ^ a b Chernoff, Barry; Buckup, Paulo Andreas; Machado-Allison, Antonio; Royero, Ramiro (1 February 1994). "Systematic Status and Neotype Designation for Autanichthys giacopinii Fernández-Yépez with Comments on the Morphology of Bryconops melanurus (Bloch)". Copeia. 1994 (1): 238–242. doi:10.2307/1446694. JSTOR 1446694. Retrieved 28 October 2022.
  5. ^ a b c d Bloch, Marcus Elieser (1794). Bloch's Oeconomische Naturgeschichte der Fische Deutschlands (in German). Vol. 4. Berlin: J. Morino & Company. p. 104. Retrieved 31 October 2022.
  6. ^ 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.
  7. ^ Chernoff, Barry; Machado-Allison, Antonio (31 December 2005). "Bryconops". doi:10.5281/zenodo.6265593. {{cite journal}}: Cite journal requires |journal= (help)
  8. ^ a b c Silva-Oliveira, Cárlison; Canto, André Luiz C.; Ribeiro, Frank Raynner V. (30 July 2015). "Bryconops munduruku (Characiformes: Characidae), a new species of fish from the lower Tapajós River basin, Brazil". Zootaxa. 3994 (1): 133–141. doi:10.11646/zootaxa.3994.1.7. PMID 26250264 – via Biotaxa.
  9. ^ a b Norman, J. R. (1 July 1926). "XI.—Descriptions of nine new freshwater fishes from French Guiana and Brazil". Annals and Magazine of Natural History. 18 (103): 91–97. doi:10.1080/00222932608633482. Retrieved 31 October 2022.
  10. ^ "Bryconops melanurus (Bloch 1794) Names". Encyclopedia of Life. Retrieved 31 October 2022.
  11. ^ Dawes, John (2001). Complete Encyclopedia of the Freshwater Aquarium (1st ed.). New York: Firefly Books. p. 195. ISBN 9781552975442. Retrieved 31 October 2022.
  12. ^ a b "Tail Light Tetra - Bryconops melanurus". Aquaticcommunity.com. Aquatic Community. Retrieved 31 October 2022.
  13. ^ Goulding, M.; Caas, C.; Barthem, R.; Forsberg, B.; Ortega, H. (2003). Amazon Headwaters - Rivers,Wildlife, and Conservation in Southeastern Peru (1st ed.). Lima, Peru: Asociación para la Conservación de la Cuenca Amazónica. ISBN 9789972402890. Retrieved 31 October 2022.
  14. ^ Reis, Roberto; Toledo-piza Ragazzo, Monica; Harold, Antony; Pavanelli, Carla; Buckup, Paulo A. (2003). "Genera incertae sedis in Characidae". Retrieved 31 October 2022. {{cite journal}}: Cite journal requires |journal= (help)
  15. ^ a b Guimarães, Karen Larissa Auzier; de Sousa, Marcos Paulo Alho; Ribeiro, Frank Raynner Vasconcelos; Porto, Jorge Ivan Rebelo; Rodrigues, Luís Reginaldo Ribeiro (21 December 2018). "DNA barcoding of fish fauna from low order streams of Tapajós River basin". PLOS ONE. 13 (12): e0209430. doi:10.1371/journal.pone.0209430. PMC 6303048. PMID 30576366.
  16. ^ Echevarría, Gabriela; González, Nirson (November 2018). "Fish taxonomic and functional diversity in mesohabitats of the River Kakada, Caura National Park, Venezuela". Nature Conservation Research. 3 (Suppl. 2). doi:10.24189/ncr.2018.048. Retrieved 20 October 2022.
  17. ^ Froese, Rainer; Pauly, Daniel (eds.) (2022). "Bryconops inpai" in FishBase. October 2022 version.
  18. ^ Froese, Rainer; Pauly, Daniel (eds.) (2022). "Bryconops magoi" in FishBase. October 2022 version.
  19. ^ Prang, Gregory. (2007). An industry analysis of the freshwater ornamental fishery with particular reference to the supply of Brazilian freshwater ornamentals to the UK market. Uakari. 3. 10.31420/uakari.v3i1.18.