Bryconops sapezal

Bryconops sapezal is a small freshwater fish native to the Rio Tapajós basin of Brazil. It is one of the more recent additions to its genus, described in 2018, and has a name that means "covered in sapê", or thatching. This originates from the Sapezal municipality of Mato Grosso, Brazil, which is type locality of B. sapezal.

Bryconops sapezal
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Iguanodectidae
Genus: Bryconops
Species:
B. sapezal
Binomial name
Bryconops sapezal
Wingert, Chuctaya, & Malabarba, 2018

Description

Bryconops sapezal ranges from 3.03 to 6.99cm SL (standard length), with the largest specimen at 9.12 cm SL.[1][2] Most species of Bryconops are within the 6 to 8 cm SL range.[3] It is a rather slender and elongate species, with a relatively small head and a body that tapers away from the origin of the dorsal fin. The scales are dark-gray on the back, silver with a bluish tint on the sides, and pale on the belly.[1] A blue tint is rare in Bryconops (only otherwise seen in B. inpai and B. marabaixo);[4][5] most species are plain silvery or slightly greenish.[6] The lower jaw ranges from dark-yellow to black. The dorsal fin is red, the adipose fin yellow, the pectoral fins translucent, and the base of the anal fin is reddish, the rest also translucent.[1]

One of the most distinctive traits of B. sapezal is the pattern on its caudal fin, which has prominent dark pigmentation in the distal region of the upper lobe and dark-gray pigmentation along the lower margin of the lower lobe. (The base of the fin is red.)[7] It can be told apart from various other species in the genus via other traits as well, such as its lack of a humeral spot and lack of a caudal-fin ocellus (eyespot).[1]

Bryconops sapezal is relatively similar in appearance to congener Bryconops rheoruber. B. rheoruber and B. sapezal both have 8–9 predorsal scales, but B. rheoruber has more scales around the circumference of its caudal peduncle (14–16 vs. 10–13 in B. sapezal).[2]

Sexual dimorphism

A feature seen in most members of Bryconops is the presence of hooks or spines on select pelvic- and anal-fin rays of mature males.[8] B. sapezal is no exception to this, bearing larger hooks on the pelvic fin than on the anal fin. There is also a slight difference in fin shape, with females bearing a more falcate (hooked) anal fin and males with a more rounded one.[1]

Taxonomy

Bryconops sapezal has retained its original name since its description in 2018.[9] There are two subgenera in Bryconops, Bryconops and Creatochanes, and B. sapezal is considered a part of the latter.[7] Members of Creatochanes are characterized by having 1–3 teeth on either side of the maxillary, having ossified and well-denticulated gill rakers, and having a relatively long maxilla.[2][6]

Etymology

The specific name "sapezal" comes from the Sapezal municipality of Mato Grosso, Brazil, which is the type locality of B. sapezal.[10] The word "sapezal" itself means "covered with sapê", and sapê is a word for "thatch" in Brazilian Portuguese.

Distribution and ecology

Bryconops sapezal is known only from various locations in the Rio Tapajos basin, including the Rio Tapajos main, Rio Juruena drainage, and Rio Papagaio.[2][7] Tributaries of the Rio Juruena are generally straight, with turbulent waters and frequent interruption by waterfalls.[11] The Rio Papagaio also has strong currents, and is usually substrated with rock.[12]

Conservation status

Bryconops sapezal has not been evaluated by the IUCN, but is facing excess survival pressures concerning its habitat. The natural range of B. sapezal extends near several dams, including one from which the holotype (original specimen) was collected.[13] (Which dam in particular was not specified in the original report.) The Tapajos is frequent collateral damage in various projects both legal and illegal, including infrastructure development and illegal gold mining; these factors place species like B. sapezal at risk.[14][15] Anthropogenic hazards are a frequent source of concern for members of Bryconops as a genus.[16]

On the other hand, B. sapezal has a good deal of native habitat contained within ecological reserves, like the Jaú National Park; It is the largest Amazon rainforest reserve, and surrounds part of the Rio Papagaio.[17][18]

References
  1. "Bryconops sapezal, Wingert & Chuctaya & Malabarba, 2018". Plazi TreatmentBank. Plazi. Retrieved 3 November 2022.
  2. Silva-Oliveira, Cárlison; Sabaj, Mark Henry; Ota, Rafaela Priscila; Py-Daniel, Lúcia H. Rapp (6 June 2019). "Bryconops rheorubrum (Characiformes: Iguanodectidae), new species from the Rio Xingu Rapids, Brazil". Proceedings of the Academy of Natural Sciences of Philadelphia. 166 (1): 1. doi:10.1635/053.166.0115. S2CID 210640024. Retrieved 17 November 2022.
  3. Froese, Rainer and Pauly, Daniel, eds. (2022). Species of Bryconops in FishBase. November 2022 version.
  4. 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 16 November 2022.
  5. Silva‐Oliveira, Cárlison; Moreira, Cristiano R.; Lima, Flávio C. T.; Py‐Daniel, Lúcia Rapp (September 2020). "The true identity of Bryconops cyrtogaster (Norman), and description of a new species of Bryconops Kner (Characiformes: Iguanodectidae) from the Rio Jari, lower Amazon basin". Journal of Fish Biology. 97 (3): 860–868. doi:10.1111/jfb.14445. PMID 32584438. S2CID 220060299.
  6. Chernoff, Barry; Machado-Allison, Antonio (31 December 2005). "Bryconops". doi:10.5281/zenodo.6265593. {{cite journal}}: Cite journal requires |journal= (help)
  7. Wingert, Juliana M.; Chuctaya, Junior; Malabarba, Luiz R. (9 May 2018). "A new species of Bryconops (Characiformes: Iguanodectidae) from the Rio Tapajós basin, Brazil". Zootaxa. 4418 (4): 379–387. doi:10.11646/zootaxa.4418.4.4. PMID 30313578. Retrieved 20 November 2022.
  8. "THE FISH FAMILIES". Field Guide to the Fishes of the Amazon, Orinoco, and Guianas, edited by Peter van der Sleen and James S. Albert, Princeton: Princeton University Press, 2017, pp. 95–96. https://doi.org/10.1515/9781400888801-009
  9. "Bryconops sapezal Wingert, Chuctaya & Malabarba, 2018". GBIF. Global Biodiversity Information System. Retrieved 20 November 2022.
  10. Scharpf, Christopher; Lazara, Kenneth J. (15 September 2020). "Order CHARACIFORMES: Families IGUANODECTIDAE, TRIPORTHEIDAE, BRYCONIDAE, CHALCEIDAE and GASTEROPELECIDAE". The ETYFish Project. Retrieved 18 November 2022.
  11. Ohara, Willian Massaharu; Loeb, Marina Vianna (2016). "Ichthyofauna of the upper Juruena river on Chapada dos Parecis, Mato Grosso, Brazil". Biota Neotropica. 16 (4). doi:10.1590/1676-0611-BN-2016-0224. Retrieved 20 November 2022.
  12. Varella, Henrique R.; Kullander, Sven O.; Lima, Flávio C. T. (2012). "Crenicichla chicha, a new species of pike cichlid (Teleostei: Cichlidae) from the rio Papagaio, upper rio Tapajós basin, Mato Grosso, Brazil". Neotropical Ichthyology. 10 (2): 233–244. doi:10.1590/S1679-62252012000200002. S2CID 85356813.
  13. Wingert, Juliana M., Chuctaya, Junior, & Malabarba, Luiz R. (2018). FIGURE 1. Bryconops sapezal, MCP 44795 in A new species of Bryconops (Characiformes: Iguanodectidae) from the Rio Tapajós basin, Brazil. In Zootaxa (Vol. 4418, Number 4, pp. 379–387). Zenodo. https://doi.org/10.5281/zenodo.1244930
  14. "'Blue River' turns brown, Illegal gold mining in Amazon raises concern". Al-Mayadeen. Al-Mayadeen Media Network. 25 January 2022. Retrieved 18 November 2022.
  15. "The Tapajos River: Hope for Sustainable Development". The Nature Conservancy. The Nature Conservancy. 6 November 2018. Retrieved 18 November 2022.
  16. "Search for "Bryconops"". IUCN Red List. International Union for the Conservation of Nature. Retrieved 13 November 2022.
  17. Rebêlo, George H.; Lugli, Luciana (September 2001). "49(3–4):1095-109". Revista de Biologia Tropical. 49 (4): 1095–1109. PMID 12189791. Retrieved 20 November 2022.
  18. Barnett, Adrian; Borges, Sérgio; Castilho, Carolina; Neri, Fernanda; Shapley, Rebecca (August 2002). "Primates of the Jaú National Park, Amazonas, Brazil". Neotropical Primates. 10 (2): 65–70. Retrieved 20 November 2022.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.