Orangefin tetra | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Characiformes |
Family: | Iguanodectidae |
Genus: | Bryconops |
Species: | B. affinis |
Binomial name | |
Bryconops affinis Günther, 1864 | |
The orangefin tetra (Bryconops affinis) [1] [2] 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.
It has a peaceful demeanor, living in schools and inhabiting the same areas as various other fish species. When it spawns, it prefers environments with plentiful vegetation. Its eggs are adhesive, and are released in batches instead of all at once.
It looks quite similar to one of its congeners, B. melanurus , hence the specific epithet "affinis" (which means "close to"). Another common name is "orangefin characin", but this is inaccurate; a characin is any fish of the family Characidae, and the orangefin tetra belongs to the family Iguanodectidae. However, it used to be classified as a member of Characidae, so the name is not outright incorrect, just outdated.
The orangefin tetra is relatively small, reaching a maximum of 12.0 cm (4.7 in) in total length; [3] this makes it similar in size to its congeners B. caudomaculatus and B. cyrtogaster . [4] The body shape is generally reminiscent of all Bryconops species, described as "smelt-like", similar to the genus Piabucus . [5] Upon close inspection, the scales of B. affinis display very faint radial lines, where the rest of the genus has stronger scale patterning. [6]
The common name "orangefin tetra" originates from the spots of bright orange on the caudal fin on both the upper and lower lobes. [7] Its dorsal fin is also orange, but this is not as evident upon first glance, and is more pronounced in some specimens than others. The scientific name "affinis" means "close to" in Latin, which is an indicator of similarity to its congener B. melanurus. [8]
The baisonym of Bryconops affinis is Tetragonopterus affinis, given by Albert Günther in 1864. [9] It has also been referred to as Creatochanes affinis and Roeboides affinis, [10] [11] though the latter of these is now used for a different species altogether. [12] The former name, however, still holds some accuracy; Creatochanes technically stands as a subgenus of Bryconops, to which B. affinis belongs (alongside B. caudomaculatus and B. melanurus). [13]
When first described by Rudolf Kner, the genus Bryconops was classified as a member of the family Characidae, which is an extraordinarily variable family of fishes. [14] However, research from Oliveira et al. in 2011 prompted Bryconops, along with Piabucus and Iguanodectes , to be moved to the family Iguanodectidae, which was revived from the work of ichthyologist Carl H. Eigenmann. [15] [16] Another common name for the orangefin tetra is "orangefin characin", but this is outdated due to the 2011 move, as a characin is any member of Characidae. [17]
Upon describing the species, Günther defined the type locality as Guyana. [18] It is also known from Paraguay, the Amazon, and Rio San Francisco. [19] Furthermore, its range includes the Mamore, Guapore, Tocantins, and Trombetas rivers. [20] Ichthyologist John D. Haseman attributed B. affinis' wide distribution to the fact that it has a more generalist nature than its congeners. [21] It has been mistakenly cited as appearing in Venezuela, but this is not the case. [22] Outside of its native range, it has been added to the Victorian Fisheries Authority's list of noxious aquatic species. [23]
The orangefin tetra is relatively placid, living in the same areas as various other fish species without dispute. [24] It has a known preference for water with a moderate or strong current, where it stays near the surface. [25] Its preference extends to areas with plentiful vegetation, which makes up part of its diet; it also feeds on various invertebrates. [3] While not an active part of the fish market in its native range, it serves as a food source for fishes that are. [26] It is also subject to infestations by gill parasites of the genus Jainus (not to be confused with the sawfly genus Janus). [27] [28]
The orangefin tetra is a batch spawner, releasing batches of eggs over a period of time as opposed to all at once. [29] The eggs adhere to the substrate where they are placed, and this is thought to be a result of structural aspects of the egg (as opposed to an additional substance secreted upon being laid). [30] [31] The zona pediculla, one of the outer layers of the egg, displays structural specializations during formation that likely play a role. [32]
The orangefin tetra is of interest to hobbyists, but it has not been evaluated by the International Union for the Conservation of Nature (IUCN); [3] [33] however, a wide distribution and hardy nature make an endangered status unlikely. Nonetheless, it is known to be exported from Guyana for use in the aquarium industry. [34] Data for less popular species, like B. affinis, is low. [35]
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.
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.
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.
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.
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.
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.
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 gracilis is a small species of freshwater fish from the rivers of South America. It is one of multiple species for which the common name "lambari" is used. Though not well-studied, it has been re-described in recent years in order to differentiate it from Bryconops alburnoides, a congener to which it bears a strong resemblance.
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.
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.
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.
Bryconops munduruku is a small freshwater fish of the family Iguanodectidae that lives in the rivers of South America. Its adipose fin is black, with a clear base, and it has two humeral spots, which is a feature it shares with few congeners. Its fins are a variety of yellow, red, black, and clear, and mature males have hooks on select fin-rays.
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 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.
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