Bryconops marabaixo | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Characiformes |
Family: | Iguanodectidae |
Genus: | Bryconops |
Species: | B. marabaixo |
Binomial name | |
Bryconops marabaixo | |
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.
Bryconops marabaixo was officially named in 2020, though it was the secondary focus of the nominal article. The study that described it had the primary purpose of solidifying a proper description for congener Bryconops cyrtogaster , to which it has some superficial resemblance.
Bryconops marabaixo is a relatively small member of its genus. The holotype, or first collected specimen, measured 6.17cm SL (standard length), and further specimens measured 5.04-6.09 cm SL. [1] Most members of Bryconops are between 6 and 8 cm SL. [2] The body, while compressed, is rather convex, especially in comparison to other members of Bryconops. [3]
The scales are generally silver, with a blue-green tint, and they are darker on B. marabaixo's back; this color changes to a yellowish or pale-brown upon preservation of a dead specimen in alcohol. [3] (A silver-to-greenish color is not uncommon in Bryconops. [4] A bluish tint is only otherwise seen in B. inpai and B. sapezal .) [5] [6] In life, the dark coloration from the back extends to the caudal peduncle and somewhat onto the base of the caudal fin. The humeral mark is middlingly conspicuous. [3]
Bryconops marabaixo bears some morphological resemblance to congeners Bryconops chernoffi and Bryconops rheoruber . In all three, there are 8–9 predorsal scales (as opposed to 10–17 in other Bryconops) and a similar position of dorsal-fin origin. In marabaixo and chernoffi, the lateral line reaches the interradial membrane (the fin membrane itself) of the caudal fin, where it does not in any other congeners. [3] Nonetheless, differentiation from B. marabaixo specifically is simple because B. chernoffi and B. rheoruber both lack a humeral spot. [3] [7]
The genus Bryconops has two subgenera, Bryconops and Creatochanes. B. marabaixo is characterized as belonging to Creatochanes by way of its teeth and gill rakers; members of Creatochanes have 1–3 teeth in either side of the maxilla e, and the gill rakers are ossified (bony) and well-denticulated. [4] [7] Both traits are seen in B. marabaixo, though it has a jaw structure more reminiscent of subgenus Bryconops. [3]
B. marabaixo has no known synonyms, and has retained its original name since discovery. [8] [9]
The specific epithet "marabaixo" originates from a collection of religious and festive practices, Marabaixo, that originated in Amapá, Brazil, the type locality of B. marabaixo. [3] [10] It is strongly associated with the resistance and cultural strength of black Brazilians, who were originally settled in the region as slaves. [10] [11] The religious aspect is tied with the saints of the Catholic church. [12]
Bryconops marabaixo is only present in the Rio Jari and the Rio Iratapuru. The latter is a tributary of the former. It is the only species of Bryconops to be found in the rio Jari, though most species of Bryconops are from other regions of the Amazon. The range of B. marabaixo seems to be limited by the Cachoeira de Santo Antônio, a major waterfall in a downstream portion of the Jari. [3]
Though B. marabaixo has not been officially evaluated, a large portion of its native range, the Rio Jari, is within the Nascentes do Lago Jari National Park. [13] This park is one of few left in the region that prioritizes biological diversity and preservation, as opposed to sustainable use of natural resources. [14] Nonetheless, it is under threat of illegal activities that include an unlawful access road that cuts through various protected areas. [15] While this is not an immediate threat to the aquatic environment of the region, it sets a precedent of deliberate anthropogenic hazard that may eventually extend into B. marabaixo's habitat.
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.
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 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 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 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 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.
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 hexalepis is a small iguanodectid fish from the rivers of Brazil. It is solely found in the drainage of the Rio Tocantins. Rather elongate and quite slender, it is considered one of the smaller species of its genus, with tall scales and large eyes.
Bryconops rheoruber is a species of freshwater fish from the rivers of Brazil. Its back scales are tan-to-cream, and its belly is silvery; the divide between the two colors is marked by a broad iridescent-silver stripe. Its fins are a mixture of pale, clear, and reddish, which contributed to its specific name. "Rheo" means "flow" or "current" in Greek, and "ruber" means "red" in Latin.
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.
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