Bryconops imitator

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Bryconops imitator
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Iguanodectidae
Genus: Bryconops
Species:
B. imitator
Binomial name
Bryconops imitator
Chernoff, Machado-Allison, Provenazo, Willink, & Petry, 2002

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.

Contents

It gets the specific epithet "imitator" from its strong resemblance to another member of the genus, Bryconops colaroja ; however, there are subtle differences in bone structure, color, and other traits that allow for differentiation. B. imitator and B. colaroja otherwise share many visual similarities that make them easy to confuse.

Description

Bryconops imitator usually reaches 7.8 cm (3.1 in) in standard length. [2] This places it close to the middle of the length range for Bryconops as a whole. [3] Its scales are generally silver with a hint of emerald-green, and one of its most distinguishing features is a bright-red tail, a trait it only shares with B. colaroja (which was named for its tail; cola- means tail and -roja means red). [4] [5] The fact that B. imitator and B. colaroja are the only two members of Bryconops - and, in fact, two of very few tetras in general - to have this specific trait is one of the reasons that B. imitator went unrecognized as long as it did. [4]

Even upon a relatively close inspection, B. imitator is easy to confuse with B. colaroja, but several differentiating facets exist. These involve features as subtle as where scales form new rows on the body; the rows of B. imitator's scales split at the seventh scale in the mid-dorsal scale row, but the rows of B. colaroja's scales split after the 5th and the 8th scale. [4] Differences in body shape are easier to see. B. imitator has a slightly more arched predorsal region, and a thinner caudal peduncle (the joint where the tail fin attaches to the body). [4]

Bryconops imitator has several differences in coloration that set it apart from other related species, not just B. colaroja. It lacks a humeral spot, a mark above the pectoral fin in some fish (including many Bryconops), and has no increase in pigmentation in the eye and cheek region. [2] The lobes of its caudal (tail) fin are equal in length, and it lacks the caudal ocellus (eyespot) seen in plenty of its congeners. [2] It also has no band of pigment at the base of its anal fin, and this specifically differentiates it from B. colanegra , which has an exaggerated stripe on its anal fin base. [6]

Taxonomy

Bryconops imitator has been considered a member of Bryconops since its designation in 2002 by Chernoff & Machado-Allison. [4] Bryconops consists of two subgenera, Bryconops and Creatochanes, and B. imitator is considered a member of Creatochanes; [4] hence, its full scientific name is Bryconops (Creatochanes) imitator. Members of Creatochanes are classified based upon having at least one tooth, up to three, in both sides of the maxillary bone. [7]

While this cannot be quantified from external observation alone, the denticulation of the gill rakers (how many denticles, or toothlike protrusions, the gill rakers have) can also play a part in classification. B. imitator's gill rakers, while perhaps the least denticulated amongst comparable species, still bear the right similarities to place it in a clade within its subgenus; this clade consists of Bryconops melanurus|B. melanurus, B. colaroja, B. colanegra, and B. imitator. [4]

Distribution and ecology

Bryconops imitator is endemic to the Caura River, a blackwater tributary of the Orinoco river. [2] It has a noted preference for sandy substrate (as opposed to rocky or clay-heavy). [8] It demonstrates similar environmental needs to its cousin B. colaroja, which contributed to their longtime synonymy, but B. colaroja is endemic to an entirely different tributary of a different river altogether (the Cuyuní river, which is a tributary of the Essequibo river). [4] [9]

Though detailed research on its specific preferences is lacking, B. imitator is known to target invertebrates. [8] The presence of gill rakers suggests that microscopic invertebrates are included, and the Caura River is not lacking. There is a plentiful population of zooplankton that rises and falls with the yearly flood cycle, though these zooplankton do not reproduce in the river itself and are instead solely washed in from the floodplains or other channels. [10]

Conservation status

The IUCN considers B. imitator to be a near-threatened species largely thanks to habitat loss and degradation. [1] Illegal gold mining is a thriving industry in Latin America as a whole, and the activities therein are damaging and endangering many habitats, not just aquatic. [11] Specific threats include mercury toxicity, [12] which is dangerous not just to inhabitants like B. imitator but also to the human communities that rely on the river systems for water. [13]

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.

<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 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.

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

Bryconops cyrtogaster is a midsize species of freshwater fish found in the Oyapock river in French Guiana and Brazil. It is overall silver, with an indistinct dark patch at the base of the tail fin that spreads onto the fin rays slightly. Originally described in 1926 under a different baisonym, it was the subject of a redescription in June 2020.

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 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 tocantinensis</i> Species of fish

Bryconops tocantinensis is a small freshwater fish from the rivers of Brazil. It has yellow-gold scales on its back and white scales on its belly, with a bright-silver stripe marking the divide between the two. It gets the name "tocantinensis" from its endemism to the upper Tocantins basin drainage - specifically, the Conceição River.

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.

Bryconops marabaixo is a small freshwater fish from the lower Amazon basin, native to the Rio Jari. It is small and silvery, with a dark-gray back, and its fins are mostly clear, though the caudal fin has a dark stripe on the lower margin of the dorsal lobe, and a spot of red pigment just above that. Like many other members of Bryconops, it has a humeral spot, which is a mark near each pectoral fin.

References

  1. 1 2 Echevarría, G. 2019. Bryconops imitator. The IUCN Red List of Threatened Species 2019: e.T167775A118038685. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T167775A118038685.en. Accessed on 06 October 2022.
  2. 1 2 3 4 Froese, Rainer; Pauly, Daniel (eds.) (2022). "Bryconops imitator" in FishBase . October 2022 version.
  3. ↑ Froese, Rainer and Pauly, Daniel, eds. (2022). Species of Bryconops in FishBase . October 2022 version.
  4. 1 2 3 4 5 6 7 8 Antonio, Machado-Allison; Chernoff, Barry; Provenzano, Francis; Willink, Phil; Petry, Paul (November 2002). "Bryconops imitator, a new species from the Caura river basin of Venezuela (Teleostei, Characiformes)". Ichthyological Explorations of Freshwaters. 13 (3): 193–202. hdl:10872/17872 . Retrieved 6 October 2022.
  5. ↑ Scharpf, Christopher; Lazara, Kenneth J. (15 September 2020). "Order CHARACIFORMES: Families IGUANODECTIDAE, TRIPORTHEIDAE, BRYCONIDAE, CHALCEIDAE and GASTEROPELECIDAE". The ETYFish Project. Retrieved 5 October 2022.
  6. ↑ Chernoff, Barry; Machado-Allison, Antonio (31 December 2005). "Bryconops". doi:10.5281/zenodo.6265593.{{cite journal}}: Cite journal requires |journal= (help)
  7. ↑ 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.
  8. 1 2 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 4 October 2022.
  9. ↑ Froese, Rainer; Pauly, Daniel (eds.) (2022). "Bryconops colaroja" in FishBase . October 2022 version.
  10. ↑ Saunders, James F.; Lewis, William M. (September 1988). "Zooplankton Abundance in the Caura River, Venezuela". Biotropica. 20 (3): 206–214. doi:10.2307/2388235. JSTOR   2388235 . Retrieved 6 October 2022.
  11. ↑ Klein, David (6 May 2022). "Interpol: Illegal Gold Mining is Devastating Latin America". OCCRP. Organized Crime and Corruption Reporting Project. Retrieved 6 October 2022.
  12. ↑ "Illegal Gold Mining". USAID. United States Agency for International Development. Retrieved 6 October 2022.
  13. ↑ Blades, Robin; Moher, Paleah (6 May 2021). "Pictures from outer space reveal the extent of illegal gold mining in Peru". The Conversation. The Conversation U.S. The Conversation. Retrieved 6 October 2022.
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