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1.
Braz. j. biol ; 82: e232868, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1153458

RESUMO

Abstract The "piaussu", Megaleporinus macrocephalus is an anostomatid fish species native to the basin of the Paraguay River, in the Pantanal biome of western Brazil. However, this species has now been recorded in a number of other drainages, including those of the upper Paraná, Uruguay, Jacuí, Doce, Mucuri, and Paraíba do Sulrivers. This study presents two new records of the occurrence of M. macrocephalus, in the basins of the Itapecuru and Mearim rivers in the state of Maranhão, in the Brazilian Northeast. The piaussu is a large-bodied fish of commercial interest that is widely raised on fish farms, and its occurrence in the Itapecuru and Mearim rivers is likely the result of individuals escaping from fish tanks when they overflow during the rainy season. Morphological analyses and sequences of the Cytochrome Oxidase Subunit I (COI) gene confirmed the taxonomic identification of the specimens as M. macrocephalus. The COI sequences were 99.66% similar to those of M. macrocephalus deposited in the BOLDSystems database. These records extend the known distribution of M. macrocephalus to the basins of the Itapecuru and Mearim rivers in the Brazilian Northeast, highlighting a new case of introduction of exotic fish species into Brazilian river basins.


Resumo Megaleporinus macrocephalus é uma espécie de peixe anostomatídeo nativa da bacia do rio Paraguai, no bioma Pantanal do oeste do Brasil. No entanto, essa espécie já foi registrada em várias outras drenagens, incluindo as dos rios Alto Paraná, Uruguai, Jacuí, Doce, Mucuri e Paraíba do Sul. Este estudo apresenta dois novos registros da ocorrência de M. macrocephalus, nas bacias dos rios Itapecuru e Mearim, no estado do Maranhão, no nordeste brasileiro. O piaussu é um peixe de grande porte, de interesse comercial, amplamente criado em pisciculturas, e sua ocorrência nos rios Itapecuru e Mearim é provavelmente o resultado de indivíduos que escapam dos tanques quando transbordam durante a estação chuvosa. Análises morfológicas e sequências do gene da subunidade I do citocromo oxidase (COI) confirmaram a identificação taxonômica dos espécimes como M. macrocephalus. As sequências de COI foram 99,66% semelhantes às de M. macrocephalus depositadas no banco de dados BOLDSystems. Esses registros estendem a conhecida distribuição de M. macrocephalus às bacias dos rios Itapecuru e Mearim, no nordeste brasileiro, destacando um novo caso de introdução de espécies exóticas de peixes nas bacias hidrográficas brasileiras.

2.
Braz J Biol ; 82: e232868, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33681896

RESUMO

The "piaussu", Megaleporinus macrocephalus is an anostomatid fish species native to the basin of the Paraguay River, in the Pantanal biome of western Brazil. However, this species has now been recorded in a number of other drainages, including those of the upper Paraná, Uruguay, Jacuí, Doce, Mucuri, and Paraíba do Sulrivers. This study presents two new records of the occurrence of M. macrocephalus, in the basins of the Itapecuru and Mearim rivers in the state of Maranhão, in the Brazilian Northeast. The piaussu is a large-bodied fish of commercial interest that is widely raised on fish farms, and its occurrence in the Itapecuru and Mearim rivers is likely the result of individuals escaping from fish tanks when they overflow during the rainy season. Morphological analyses and sequences of the Cytochrome Oxidase Subunit I (COI) gene confirmed the taxonomic identification of the specimens as M. macrocephalus. The COI sequences were 99.66% similar to those of M. macrocephalus deposited in the BOLDSystems database. These records extend the known distribution of M. macrocephalus to the basins of the Itapecuru and Mearim rivers in the Brazilian Northeast, highlighting a new case of introduction of exotic fish species into Brazilian river basins.


Assuntos
Caraciformes , Rios , Animais , Brasil , Caraciformes/genética , Humanos , Paraguai , Uruguai
3.
J Fish Biol ; 88(2): 459-76, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26660534

RESUMO

Two new species of Hyphessobrycon are described from the headwaters of the Tapajós and Xingu River basins, Pará, Brazil. Both new species can be distinguished from congeners by the presence of a vertically elongate humeral blotch, a conspicuous round to vertically oblong caudal-peduncle blotch not extending onto the distal portions of the middle caudal-fin rays, a conspicuous blotch on the central portion of the third infraorbital immediately ventral to the eye, the lack of a conspicuous longitudinal stripe and the lack of sexual dimorphism in the extension of the caudal-peduncle blotch. Hyphessobrycon delimai n. sp. can be distinguished from Hyphessobrycon krenakore n. sp. by the extent of the caudal-peduncle blotch which extends across most of the caudal-peduncle depth (v. restricted to the middle portion of the caudal peduncle), the presence of dark chromatophores uniformly scattered along the length of the interradial membranes of the dorsal, anal and caudal fins (v. concentrated on the distal one-half or one-fourth of the interradial membranes) and the absence of small bony processes on the pelvic and anal fins of mature males (v. small bony processes present).


Assuntos
Characidae/anatomia & histologia , Characidae/classificação , Nadadeiras de Animais/anatomia & histologia , Animais , Brasil , Feminino , Masculino , Rios , Dente/anatomia & histologia
4.
J Fish Biol ; 87(4): 860-75, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26287270

RESUMO

A new species of the catfish genus Centromochlus (Auchenipteridae, Centromochlinae) is described. The new species is diagnosed by having numerous dark rounded blotches over the body and fins, dorsal-fin spine with serrations anteriorly and smooth posteriorly, anal fin of mature males with three unbranched and seven branched rays, anterior nuchal plate absent and posterior nuchal plate not extended ventrally. The new species is described from a small stream in the Estação Ecológica Serra Geral de Tocantins, a natural reserve in the centre of the Brazilian Cerrado, close to the watershed between the Rio Tocantins and the Rio São Francisco basins. The new species is possibly the sister taxon to the recently described Centromochlus meridionalis from the upper Rio Tapajós. Those two species share with Centromochlus perugiae, from the upper Amazon and upper Paraguay, derived features associated with the modified anal fin in sexually mature males.


Assuntos
Peixes-Gato/classificação , Nadadeiras de Animais , Animais , Brasil , Peixes-Gato/anatomia & histologia , Feminino , Masculino , Filogenia , Caracteres Sexuais , Especificidade da Espécie
5.
J Fish Biol ; 84(5): 1539-50, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24773543

RESUMO

A new species of Rhinopetitia is described from the Rio Teles Pires, a major tributary of the Rio Tapajós. The new taxon is distinguished from its only congener, Rhinopetitia myersi, by having all premaxillary teeth in both rows with seven to nine cusps, maxillary teeth with seven or eight cusps, a distinct dark midlateral stripe on the body and a round humeral blotch (v. outer series of premaxillary teeth with three cusps and inner series of premaxillary teeth with three to five cusps, maxillary teeth with three to five cusps, the absence of a dark midlateral stripe and humeral blotch). Putative characters suggesting a close relationship between Rhinopetitia, Bryconacidnus, Ceratobranchia, Monotocheirodon, Odontostoechus, Othonocheirodus and Rhinobrycon are presented. This putative clade is included in the Stevardiinae, a monophyletic group within the Characidae.


Assuntos
Characidae/anatomia & histologia , Characidae/classificação , Animais , Brasil , Feminino , Masculino , Rios , Caracteres Sexuais
6.
Braz J Biol ; 73(2): 259-70, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23917553

RESUMO

A study on the fish assemblage of the Ipanema River, a small affluent of the Tietê River basin in southeastern Brazil, was performed aiming to look for structural patterns of species diversity in small lowland lotic environments. Fish samplings were performed every two months from June 2003 to April 2004 at four sample sites located on the lower stretch of the river. Local assemblage showed to be species rich, with fifty-two species belonging to Characiformes (25 spp.), Siluriformes (19 spp.), Cyprinodontiformes (3 spp.), Gymnotiformes (2 spp.), Perciformes (2 spp.), and Synbranchiformes (1 sp.). Fish fauna was composed of small-sized species (<200 mm SL) and by individuals of medium (up to 400 mm SL) to large (more than 400 mm SL) sized species. The Ipanema River, such as other small lotic transitional environments in the upper Paraná River drainage, is considered important for conservation of fish fauna because they cover available habitats for persistent populations of small-sized species and for non-persistent individuals or shoals of medium and large-sized fish species, which occupy other habitats along their life-history (e. g. floodplains, oxbow lakes, main channel of great rivers). The importance of the Ipanema River basin for fish fauna conservation is also reinforced by the fact that it is located in a highly impacted region of southeastern Brazil, near the São Paulo metropolitan area.


Assuntos
Biodiversidade , Monitoramento Ambiental , Peixes/classificação , Rios , Animais , Brasil , Densidade Demográfica , Estações do Ano
7.
J Fish Biol ; 83(5): 1128-60, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24580659

RESUMO

Two new species of Leporinus are described from tributaries of the Rio Amazonas in Brazil. One species is known from the Jari and Tapajós River basins, and is identified on the basis of a gas bladder reduced in size, a dark midlateral stripe on the body, dark transverse bars on the dorsum, a subinferior mouth, three teeth on the premaxilla, four teeth on the dentary and 16 scale rows around the caudal peduncle. The second new species is known from the Tocantins, Xingu and Tapajós River basins, and is identified on the basis of three dark longitudinal stripes on the body, a subinferior mouth, three teeth on the premaxilla, four teeth on the dentary and 12 scale rows around the caudal peduncle. In addition, Leporinus striatus is redescribed based on type and additional specimens from the Río de La Plata, Amazonas, Orinoco, Atrato, Magdalena and Sinu River basins. Leporinus striatus is identified on the basis of four dark longitudinal stripes on the body, a subterminal mouth, three teeth on the premaxilla, four teeth on the dentary and 16 scale rows around the caudal peduncle.


Assuntos
Caraciformes/anatomia & histologia , Caraciformes/classificação , Animais , Brasil , Rios
8.
Braz J Biol ; 71(2): 375-80, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21755154

RESUMO

The Itapecuru is a relatively large river in the northeastern Brazilian state of Maranhão. During several expeditions to this basin, we collected 69 fish species belonging to 65 genera, 29 families and 10 orders. Characiformes and Siluriformes were the orders with the largest number of species and Characidae, Loricariidae, Cichlidae, Auchenipteridae and Pimelodidae were the richest families. About 30% of the fish fauna of the Itapecuru basin is endemic or restricted to northeastern Brazil. Just over a fifth (22%) of the species is also known to occur in the Amazon basin and only a few are more widely distributed in South American.


Assuntos
Biodiversidade , Peixes/classificação , Rios , Animais , Brasil , Densidade Demográfica
9.
J Fish Biol ; 75(10): 2615-28, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20738511

RESUMO

A new species of Moenkhausia is described from Rio Xingu and Rio Tapajós basins, Brazil. The new species is distinguished from its congeners, except from Moenkhausia moisae, by having more scales in the lateral series, 43-47 (v. 23-41 in the remaining congeners). The new species is distinguished from M. moisae by its colour pattern, which consists of a dark midlateral stripe, and an asymmetrical caudal blotch (inconspicuous or faded in specimens from the Rio Arinos) continuous with the midlateral stripe (v. narrow dark midlateral line and conspicuous, regularly rounded and symmetrical blotch not continuous with the midlateral line). The new species is putatively assumed to be mimetic to Jupiaba apenima, in the Rio Xingu and Rio Teles Pires drainages, and to Jupiaba yarina in the Rio Arinos. The two species of Jupiaba are sympatric and remarkably similar in size, general external morphology and colouration to the new species. A small difference occurs in the colouration between the two species of Jupiaba and is also observed in the two respectively sympatric morphotypes of the new species of Moenkhausia. The occurrence of polymorphic Batesian mimicry is therefore discussed for neotropical freshwater fishes.


Assuntos
Peixes/anatomia & histologia , Peixes/classificação , Animais , Brasil , Rios
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