Bryconops colanegra

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

Bryconops colanegra is a small, slender-bodied species of freshwater fish from South America, about 3.5 in (8.8 cm) 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.

Contents

Description

Bryconops colanegra is one of the smaller members of the genus Bryconops, at 8.8 cm (3.5 in) standard length. [1] It has dark back scales that fade to a silvery belly, aside from a patch in the opercular and cheek region that bears definite pigmentation (something that also appears in congener B. melanurus ). [2] The anal fin has a broad band of black along the base, which is a feature that B. colanegra does not share with any other members of the genus. [3]

The distinct black caudal fin that Bryconops colanegra has is the origin of its scientific name: "cola-" means "tail", and "negra" means "black". [4] This is one way to differentiate it from several congeners. B. colaroja , for example, has a red caudal fin, and the tailspot tetra (B. caudomaculatus) has a large, distinct spot on its tail. Though its pigmentation is its main feature, there is usually a hint of red in the caudal fin nonetheless. [2]

The teeth are multicuspid, and the fish is equipped with a set of gill rakers that are notably denticulated - that is, covered in tooth-like protrusions. [2] The higher denticulation level is in contrast with congener B. colaroja, whose gill rakers have fewer protrusions. Multicuspid teeth are a feature that the genus Bryconops shares with sister clade Iguanodectinae. [5]

Taxonomy

Described in 1999, [6] Bryconops colanegra belongs to the subgenus Creatochanes, making its full scientific name Bryconops (Creatochanes) colanegra. [2] In the same study that elevated it to species status, its congener B. colaroja was also named. [2] Though it has a scientific name that means "black tail", B. colanegra does not have an accepted common name. [7] The name "black-tailed tetra" has been suggested.

Bryconops colanegra used to be considered a characin, or a member of the family Characidae. However, research in 2011 prompted that the genus Bryconops, along with the genera Iguanodectes and Piabucus , be moved to the family Iguanodectidae. [8] Subsequently, B. colanegra's current accepted classification is as an Iguanodectid fish. [9] It remains a member of the order Characiformes.

Habitat and ecology

Bryconops colanegra is found largely in the Caroní River, which stretches across Venezuela (not to be confused with the Caroni River in Trinidad and Tobago). [10] [11] The Caroní, as a blackwater river, has a high concentration of humic substances. Because microbial activity is what causes blackwater conditions, blackwater rivers are poorly oxygenated (with microbes taking up whatever oxygen they can), indicating that B. colanegra does not need oxygen-rich water to survive. [12]

Conservation status

Because the Caroní River is facing construction of several hydroelectric dams and already provides 70% of Venezuela's hydroelectric power, the ecology of the region faces repercussions, possibly severe. [13] The local ecosystems are also threatened by current mining projects, various types of which have been occurring in the region since the 1990s. [14] As it currently stands, however, B. colanegra is considered a species of least concern on the IUCN Red List, based upon a wide native range - the Caroní is the longest single river in Venezuela. [15]

Bryconops colanegra is known to be taken from the wild for the aquarium industry. Its trade is not restricted nor blocked in any country, and it is not in widespread use as a captive animal. [16] Capture from the wild is also not considered a threat to its population numbers; its greatest threat is perhaps habitat disruption by way of human activity. [15] This is something it shares with other members of the genus that have been evaluated. [17]

Diet

Though little of B. colanegra's diet specifically has been studied, other members of the genus are known to be insectivorous, displaying differing preferences for invertebrates from various habitats. For example, the tailspot tetra (B. caudomaculatus) is known to jump out of the water to catch flying insects, while B. alburnoides demonstrates a taste for terrestrial insects. [18] [19] The orangefin tetra, B. affinis, makes plants a more prominent part of its diet. [20] It can reasonably be assumed that B. colanegra's diet is similar to those of its congeners.

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.

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

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.

<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

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  2. 1 2 3 4 5 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 10 April 2022.
  3. 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 10 April 2022.
  4. Scharpf, Christopher; Lazara, Kenneth J. (15 September 2020). "Order CHARACIFORMES: Families IGUANODECTIDAE, TRIPORTHEIDAE, BRYCONIDAE, CHALCEIDAE and GASTEROPELECIDAE". The ETYFish Project. Retrieved 6 April 2022.
  5. 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.
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  14. Leotaud, Valentina Ruiz (22 April 2020). "Venezuela allows gold mining in river basins". Mining.com. Glacier Media . Retrieved 10 April 2022.
  15. 1 2 Echevarría, G. (18 April 2017). "Bryconops colanegra: Echevarría, G.: The IUCN Red List of Threatened Species 2019: e.T118038855A118038861". IUCN Red List. International Union for the Conservation of Nature. doi: 10.2305/IUCN.UK.2019-3.RLTS.T118038855A118038861.en . Retrieved 10 April 2022.
  16. Fredberg, Joshua; McNeil, Dale (August 2010). Review of non-native ornamental fish species grey listed in Australia (PDF). West Beach, SA: SARDI Aquatic Sciences. ISBN   978-1-921563-35-5 . Retrieved 10 April 2022.
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  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 . Retrieved 10 April 2022.
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