Bryconops colaroja

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Bryconops colaroja
Bryconops colaroja preserved.png
Preserved specimen
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Iguanodectidae
Genus: Bryconops
Species:
B. colaroja
Binomial name
Bryconops colaroja

Bryconops colaroja is a small species of fish endemic to tributaries and creeks of the Cuyuni River basin in Venezuela. The specific epithet "colaroja" means "red tailed", and it gets this name from its most distinctive feature - a deep red caudal fin, largely unique amongst members of its genus.

Contents

Description

Bryconops colaroja is one of the smaller members of the genus Bryconops , measuring around 7.8 cm (3.1 in) in standard length. [2] In general, the genus Bryconops has a similar body shape to sister genus Piabucus , described as resembling a minnow or smelt. [3] Its scales are mostly greenish-silver, slightly darker on the back than on the rest of the body. The uniform gradient of the scales, lacking prominent markings, is a feature that can be used to differentiate it from other members of the genus; for example, B. colanegra and B. melanurus have distinct blotches of pigmentation in the cheek and eye region. [4]

Bryconops colaroja is the only member of the genus Bryconops to have a caudal fin that is completely red, aside from congener Bryconops imitator (which gets its name from its similarity to B. colaroja). [5] [6] The margins of the fin rays are the only places where melanophores are present, making dark lines radiate inwards from the fin margin. [4] This distinct color is the origin of the fish's scientific name; "cola" means "tail", and "roja" means "red". [7] It is sometimes called the redtailed bryconops because of this, [8] but this is not in wide use, and B. colaroja has no accepted common name. [9]

Though Bryconops colaroja has gill rakers that are notably denticulated - that is, adorned with toothlike protrusions - its congener B. colanegra is known to have gill rakers with higher denticulation. [4] The teeth are multicuspid, which is a feature that the Bryconops clade shares with sister clade Iguanodectinae. [10]

Taxonomy

Bryconops colaroja was described in 1999 as a part of the subgenus Creatochanes, making its full name Bryconops (Creatochanes) colaroja. [4] It has no synonyms, nor is it often mistaken for its congeners, aside from B. imitator. [11] The red tail makes it fairly easy to identify.

Bryconops colaroja, as with all members of the genus Bryconops, was once considered a part of the family Characidae, and is still listed there by some sources. [12] [13] However, research in 2011 by Oliveira et al. moved the genera Bryconops, Iguanodectes , and Piabucus to the family Iguanodectidae, [14] which is where B. colaroja currently stands. [2] [11]

Habitat and ecology

Bryconops colaroja is known only from the Cuyuní river basin, leaning on the border between Venezuela and Guyana; [2] [15] however, it has not been collected from the Cuyuni river main, only smaller creeks and tributaries. [4] It demonstrates a preference for slightly acidic waters, as well as a rocky or sandy substrate. [1]

The blackwater nature of B. colaroja's habitat indicates that it does not need well-oxygenated waters to survive. [4] Part of what characterizes a blackwater river is a high concentration of humic substances, which are the result of microbial activity. This microbial activity consumes much of the oxygen in the water, and as such fish with high-oxygen needs are not suited for blackwater environments. [16]

Diet

The diet of Bryconops colaroja hasn't been the subject of extensive study on its own, but other members of the genus are known to be largely insectivorous, and have noted preferences for invertebrates of various origins. The orangefin tetra (B. affinis) makes plants a more prominent part of its diet, though it still eats invertebrates. [17] The tailspot tetra (B. caudomaculatus) jumps out of the water to catch flying insects, and B. alburnoides demonstrates a taste for terrestrial insects. [18] [19] Based on the most current information, B. colaroja can reasonably be assumed to be an insectivore that takes supplemental plant material.

Conservation status

Though little is known of B. colaroja's population trends, it is considered a species of least concern by the IUCN. [1] A potential threat is that the Cuyuni River main is regularly threatened by mining activity; the waters have been disturbed and riverbanks destroyed in the past, as it is a source of gold. [20] The Cuyuni river is generally in poor health, which places B. colaroja (as well as the other native species) at an increased risk of endangerment. [21] However, its presence has been noted by mining operations in the past, which in turn has increased their willingness to take precautions to protect it. [8]

Related Research Articles

<i>Bryconops</i> Genus of fishes

Bryconops is a genus of freshwater fish in the family Iguanodectidae from South America. It consists of small fish, all under half-a-foot long, with slender bodies and silvery scales, though there is some mild color variation. Several species can be identified by way of a humeral patch, and others have a reddish ocellus, or eyespot, on one or both lobes of the dorsal fin.

<span class="mw-page-title-main">Iguanodectidae</span> Family of fish

Iguanodectidae is a family of freshwater fish in the order Characiformes that lives in South America. It is home to the subfamily Iguanodectinae and the monotypic Bryconops clade. Several species in the family, such as the green line lizard tetra, the tailspot tetra, and the orangefin tetra, are sometimes taken as aquarium fish.

<span class="mw-page-title-main">Orangefin tetra</span> Species of fish

The orangefin tetra 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.

<i>Bryconops alburnoides</i> Species of fish

Bryconops alburnoides is a small freshwater fish, approximately 6 inches long at its largest, that lives in the rivers of South America. It has a slender body, with a yellowish dorsal fin and yellow-tinged back scales that fade into silver on its belly. It is largely an insectivore that picks land-dwelling insects from the riverbanks, though it eats much more whenever rain washes prey into the water.

<span class="mw-page-title-main">Tailspot tetra</span> Species of fish

The tailspot tetra is a freshwater fish that lives in the coastal river regions of upper South America. Both its common and scientific names reference the distinct spot of color present on the tail fin, which is one of its defining characteristics. It is a small fish, reaching 4.8 in at its longest. Despite its small size, it is an active swimmer, with a preference for fast-flowing waters.

Bryconops colanegra is a small, slender-bodied species of freshwater fish from South America, about 3.5 in long. It has a black tail fin that bears hints of red, and its scales are dark along the back, transitioning to a silver belly. It is endemic to a single river system in Venezuela, the Rio Caroní.

<i>Bryconops collettei</i> Species of fish

Bryconops collettei is a small freshwater fish from the rivers of South America. It is mostly silvery, with notable green iridescence on its sides, and a diffuse ocellus (eyespot) on the upper lobe of the caudal fin. Before its distinction as a separate species, specimens of B. collettei were misidentified as specimens of Bryconops caudomaculatus due to several morphological similarities, including a caudal ocellus and generally similar fin coloration.

Bryconops disruptus is a small freshwater fish of the family Iguanodectidae. It is only found in the Rio Negro in South America. Like the rest of the genus Bryconops, B. disruptus is silvery in color, with a relatively deep chest and a notable set of teeth. The specific epithet "disruptus" refers to the incomplete lateral line.

Bryconops durbinae, sometimes listed under the name Bryconops durbini, is a small species of freshwater fish in the family Iguanodectidae. It is the smallest species of the genus Bryconops, and is endemic to the Tapajós river basin in Brazil.

<i>Bryconops giacopinii</i> Species of fish

Bryconops giacopinii is a mid-sized species of freshwater fish in the family Iguanodectidae. It is the largest member of the genus Bryconops, and is therefore difficult to confuse with any of its congeners. With a diet that consists largely of land-dwelling insects, it serves as an important link between the terrestrial and aquatic aspects of its native range.

Bryconops humeralis is a small freshwater fish distributed across northern South America. The name "humeralis" means "relating to the shoulder", in reference to the distinct humeral patches that the fish sports. It is slightly longer than average in terms of the genus Bryconops, though still firmly within the standard range, and is slightly more slender than is usual for its congeners.

Bryconops imitator is a small freshwater fish that lives in the rivers of South America. It is a small, silvery fish with a bright red tail fin that is known to eat invertebrates, like insects and freshwater zooplankton.

Bryconops inpai is a small freshwater fish native to the rivers of South America. It only lives in two particular river systems - the Casiquiare and Negro - which means that its range is restricted to the northern half of the continent. It has indistinct humeral spots, and is bluish-silver in life, which is unusual for members of Bryconops; they are more often plain silver or greenish-silver.

<i>Bryconops magoi</i> Species of fish

Bryconops magoi is a small species of fish from South America. It is only found in Venezuela, along with sister species Bryconops collettei. Its tail-fin markings help to differentiate it from various congeners, as does its fairly restricted range. It is most closely related to B. collettei and Bryconops caudomaculatus, and it was once considered synonymous with the latter; specimens of B. magoi and B. collettei both were routinely misidentified as B. caudomaculatus before being given species distinction.

<i>Bryconops melanurus</i> Species of fish

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.

<i>Bryconops piracolina</i> Species of fish

Bryconops piracolina is a small fish that inhabits the waters of Brazil. It is slender and silvery in color, like many fish in Bryconops, but can be distinguished from other members by way of its dorsal fin, which has a black patch of color extending up from the fin-base; congeners usually have light pigment in the dorsal fin, or a brighter color.

Bryconops vibex is a small freshwater fish from the rivers of Venezuela, known solely from the Rio Cataniapo. The body is slender, though with an element of sturdiness, and it has one humeral spot by each pectoral fin. It bears visual similarities to several congeners, but can be differentiated by way of many factors.

Bryconops allisoni is a species of freshwater fish known from the rivers of Brazil. It is a recent addition to the genus (2019), currently considered a member incertae sedis. Its name honors Antonio Machado-Allison, an ichthyologist responsible for a great deal of work on the genus Bryconops.

Bryconops chernoffi is a species of freshwater fish that inhabits the rivers of Brazil. Specifically, it is found in the Rio Maicuru and Rio Ipixuna; the latter is a tributary of the former, which is a tributary of the Amazon river main. B. chernoffi demonstrates a preference for clear-water streams with sandy and rocky bottoms.

<i>Bryconops florenceae</i> Species of fish

Bryconops florenceae is a small freshwater fish that inhabits the rivers of South America. Comprehensive research is lacking due to B. florenceae being the most recently described of the genus, but researchers believe it to be a relatively widespread species. It is found throughout the Maroni, Mana, and Sinnamary river basins, which defines its range within Suriname and French Guiana.

References

  1. 1 2 3 Echevarría, G. 2019. Bryconops colaroja. The IUCN Red List of Threatened Species 2019: e.T118038882A118038887. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T118038882A118038887.en. Accessed on 23 April 2022.
  2. 1 2 3 Froese, Rainer; Pauly, Daniel (eds.) (2022). "Bryconops colaroja" in FishBase . April 2022 version.
  3. ↑ "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
  4. 1 2 3 4 5 6 Chernoff, Barry; Machado-Allison, Antonio (23 February 2018). "Bryconops colaroja and B. colanegra, two new species from the Cuyuni and Caroni drainages of South America (Teleostei: Characidae)". Ichthyological Exploration of Freshwaters. 10 (4): 355–370. hdl:10872/17856 . Retrieved 22 April 2022.
  5. ↑ 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): 1. doi:10.11646/zootaxa.1094.1.1 . Retrieved 22 April 2022.
  6. ↑ Wingert, Juliana Mariani; Malabarba, Luiz Roberto (4 April 2011). "Descrição de duas novas espécies de Bryconops (Teleostei: Characidae) da Bacia do Rio Amazonas". hdl:10183/28524 . Retrieved 22 April 2022.{{cite journal}}: Cite journal requires |journal= (help)
  7. ↑ Scharpf, Christopher; Lazara, Kenneth J. (15 September 2020). "Order CHARACIFORMES: Families IGUANODECTIDAE, TRIPORTHEIDAE, BRYCONIDAE, CHALCEIDAE and GASTEROPELECIDAE". The ETYFish Project. Retrieved 22 April 2022.
  8. 1 2 Lambert, Richard J.; Carlsson, José Texidor; Miranda, Hugo M.; Altman, Kathleen A.; Malensek, Grant A. (26 March 2018). "Technical Report on the Siembra Minera Project, Bolivar State, Venezuela" (PDF). Retrieved 22 April 2022.{{cite journal}}: Cite journal requires |journal= (help)
  9. ↑ "Bryconops colaroja Chernoff & Machado-Allison 1999". Encyclopedia of Life. Retrieved 23 April 2022.
  10. ↑ Vari, Richard P. (26 January 1977). "Notes on the characoid subfamily Iguanodectinae, with a description of a new species". American Museum Novitates (2612). hdl:2246/2012 – via AMNH Digital Repository.
  11. 1 2 "Bryconops colanegra Chernoff & Machado-Allison, 1999". World Register of Marine Species. Retrieved 22 April 2022.
  12. ↑ "Bryconops colaroja Chernoff and Machado-Allison, 1999". Integrated Taxonomic Information System. Retrieved 22 April 2022.
  13. ↑ Myers, P.; Espinosa, R.; Parr, C. S.; Jones, T.; Hammond, G. S.; Dewey, T. A. "Bryconops colaroja Classification". Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 22 April 2022.
  14. ↑ Oliveira, C., Avelino, G.S., Abe, K.T. et al. ()26 September 2011). Phylogenetic relationships within the speciose family Characidae (Teleostei: Ostariophysi: Characiformes) based on multilocus analysis and extensive ingroup sampling. BMC Evol Biol. 11(275). https://doi.org/10.1186/1471-2148-11-275. Retrieved 10 April 2022.
  15. ↑ Petry, Paulo; Hales, Jennifer. "Orinoco Guiana Shield". Freshwater Ecoregions of the World. Retrieved 10 April 2022.
  16. ↑ "Hypoxic blackwater events and water quality". Department of Agriculture, Water and the Environment. Australian Government. 2016. Retrieved 22 April 2022.
  17. ↑ Froese, Rainer; Pauly, Daniel (eds.) (2022). "Bryconops affinis" in FishBase . April 2022 version.
  18. ↑ Costa-Pereira, Raul; Severo-Neto, Francisco (June 2012). "Dining out: Bryconops caudomaculatus jumps out of water to catch flies". Revista chilena de historia natural. 85 (2): 241–244. doi: 10.4067/S0716-078X2012000200012 . ISSN   0716-078X.
  19. ↑ da Silva, Cylene C.; Ferreira, Efrem J. G.; de Deus, Cláudia P. (28 June 2008). "Diet of Bryconops alburnoides and B. caudomaculatus (Osteichthyes: Characiformes) in the region affected by Balbina Hydroelectric Dam (Amazon drainage, Brazil)". Neotropical Ichthyology. 6 (2): 237–242. doi: 10.1590/S1679-62252008000200011 .
  20. ↑ "Brazilian dredge owner fined $12m for ripping up part of Cuyuni River bank". Stabroek News. Stabroek News. 15 September 2020. Retrieved 22 April 2022.
  21. ↑ Duplaix, Nicole (October 2009). "Bioassessment of the Cuyuni River near Aurora, Guyana, Environmental and Economic Implications" (PDF). Environmental Resources Management. Retrieved 22 April 2022.
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