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| Registros recuperados: 1.204 | |
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| Vizziano Cantonnet,Denise; Mateo,Magdalena; Alberro,Andrés; Barrios,Florencia; Fostier,Alexis. |
| The aim was to investigate the major C21 steroids produced by spermiating white croaker Micropogonias furnieri (Sciaenidae) in order to establish the potential mediator of gamete maturation in males of this species. The testes steroid production at the spawning season was identified incubating the 3H-17-hydroxy-4-pregnene-3,20-dione precursor through thin layer chromatography, high pressure liquid chromatography, enzymatic oxydation, acetylation and immunochemistry analyses. 17,20β-Dihydroxy-4-pregnen-3-one (17,20β-P) and 11β,17,21-Trihydroxy-4-pregnene-3,20-dione (cortisol) were the main metabolites produced. Contrary to what we expected, 17,20β,21-Trihydroxy-4-pregnen-3-one was not detected. Circulating levels of 17,20β-P were undetectable in immature... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Male gonad; Maturing steroids; Reproduction; Steroid synthesis; White croaker. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000300613 |
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| Honji,Renato M.; Caneppele,Danilo; Pandolfi,Matias; Nostro,Fabiana L. Lo; Moreira,Renata G.. |
| ABSTRACT Little is known about reproductive biology of endangered Steindachneridion parahybae , a gonochoristic teleost species inhabiting the Paraíba do Sul River Basin, and herein is the first description of intersex in S. parahybae juvenile. The normal appearance of ovaries and testes in juvenile from the same lot of breeding were also described for comparison, even as cytogenetic analysis was performed in these juveniles. One specimen was a priori classified as female due to the macroscopic characteristic of ovaries, with small yellow oocytes, without fringes (a main characteristic of catfish male), and larger than testes; however the microscopic analysis revealed the presence of ovotestes, including the complete spermatogenesis. S. parahybae had... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Histology; Karyotype; Ovary; Ovotestes; Testicles. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000400206 |
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| Trajano,Eleonora; Secutti,Sandro; Pereira,Edson H. L.; Reis,Roberto E.. |
| A cave population of the armored catfish Isbrueckerichthys alipionis is reported from the Santana Cave, in the rio Betari watershed, Upper Ribeira karst area, Iporanga, São Paulo State, southeastern Brazil. The cave population was compared to an epigean population of I. alipionis and no significant differences where found in morphology or degree of pigmentation. As the cave population is known for at least 30 years and is apparently isolated from epigean streams, it is classified as troglophilic. The discovery of this troglophilic species in the Santana Cave is an additional strong argument for the conservation of that cave. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cave Fish; Troglophilic; Neotropical; Conservation; Santana Cave. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000400017 |
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| Muñoz-Ramírez,Carlos P.; Briones,Raul; Colin,Nicole; Fierro,Pablo; Górski,Konrad; Jara,Alfonso; Manosalva,Aliro. |
| ABSTRACT The ancient catfish family Diplomystidae, with seven species endemic to rivers of southern South America, represents one of the oldest branches of the diverse order Siluriformes. With most species endangered, new reports of these species become extremely valuable for conservation. Currently, it is assumed that Diplomystes species inhabit only Andean (large) basins, and that they are extinct from coastal (small) basins from which their presence have not been recorded since 1919. Here, we document new records of the family Diplomystidae in the Laraquete and Carampangue basins, two coastal basins from the Nahuelbuta Coast Range, Chile, with no previous reports. This finding represents the rediscovery of the genus in coastal basins in more than a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Management Unit; Mitochondrial DNA; Rare Species; Streams; Threatened Species. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000100208 |
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| Malabarba,Maria Claudia; Lundberg,John G.. |
| A new loricariid catfish is described from the Tremembé Formation (Late Oligocene to Early Miocene) sediments of the Taubaté Basin in eastern São Paulo State, Brazil. Taubateia paraiba, new genus and species, is based on a single specimen preserved as a ventral-side impression of an articulated partial neurocranium, dorsal elements of the pectoral girdle and anterior vertebrae. The fossil is identified as belonging to family Loricariidae based on obvious overall similarity and the presence of diagnostic derived characters such as: odontodes, dorsal margin of metapterygoid contacting lateral ethmoid, presence of mesethmoid disk (condyle), and compound pterotic-supracleithrum bone. Also, as in most loricariids, the ossified transcapular (Baudelot's) ligament... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tremembé Formation; Fossil loricariid; Oligocene-Miocene; Neurocranium; Taubateia paraiba; Anterior vertebrae. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000300005 |
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| López-Rodríguez,Nathalia C.; Barros,Cíntia M. de; Petry,Ana Cristina. |
| ABSTRACT This study proposes eight stages according to the main discernible changes recorded throughout the embryonic development of Jenynsia multidentata. The development of morphological embryo structures, pigmentation, and changes in tissues connecting mother and embryo were included in the stage characterization. From the fertilized egg (Stage 1), an embryo reaches the intermediary stages when presenting yolk syncytial layer (Stage 2), initial pigmentation of the outer layers of the retina and dorsal region of the head (Stage 3), and the sprouting of the caudal (Stage 4), dorsal and anal fins (Stage 5). During the later stages, the ovarian folds enter the gills, and the body pigmentation becomes more intense (Stage 6), the body becomes elongated (Stage... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Developmental stages; Dry weight; Matrotrophy; Morphology; Viviparity. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000400206 |
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| Júlio Júnior,Horácio Ferreira; Tós,Claudenice Dei; Agostinho,Ângelo Antonio; Pavanelli,Carla Simone. |
| Based on long-term studies in the upper rio Paraná basin, in addition to a broad review of literature and other information, we were able to identify 33 species of native fishes in the lower rio Paraná basin that successfully colonized the upper rio Paraná after Itaipu impoundment, that flooded the natural geographic barrier constituted by the Sete Quedas Falls. These species belong to six Orders, encompassing two of Myliobatiformes, six of Characiformes, 17 of Siluriformes, six of Gymnotiformes, one of Perciformes, and one of Pleuronectiformes. Extensive remarks regarding each species, including their influence upon the native assemblage, in addition to comments on other non-indigenous species, are also provided. We conclude that, in spite of its... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Invasive species; Biodiversity; Reservoir Impacts; Ecoregion; Sete Quedas Falls. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000400021 |
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| Pamponet,Vanessa de Carvalho Cayres; Carneiro,Paulo Luiz Souza; Affonso,Paulo Roberto Antunes de Mello; Miranda,Viviam Souto; Silva Júnior,Juvenal Cordeiro; Oliveira,Claudine Gonçalves de; Gaiotto,Fernanda Amato. |
| Few reports are available about the ichthyofauna of typical semi-arid rivers, although the regional diversity has been constantly threatened by human activities, mainly related to impoundment and construction of dams. The goal of the present work was to evaluate using different methods, the population genetic structure of a characin fish, Astyanax aff. bimaculatus, widespread throughout hydrographic basins of Bahia, Northeastern Brazil. Morphological (meristic and morphometric data), cytogenetic (karyotype and Ag-NOR), and molecular (RAPD and SPAR) analyses were carried out in specimens collected upstream and downstream of Pedra Dam, in the main channel of Contas River (Contas River Basin), and in the Mineiro stream, which belongs to the adjacent Recôncavo... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Morphometry; Cytogenetics; RAPD; Population structure; Contas River. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000400010 |
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| Zawadzki,Cláudio H.; Birindelli,José L. O.; Lima,Flávio C. T.. |
| A new armored catfish species of the genus Hypostomus is described from the upper rio Xingu basin, Mato Grosso State, Brazil. The new species is diagnosed from congeners by having high number of teeth (58 to 101, mean 77 on premaxilla, and 58 to 105, mean 80 on dentary), dark spots over body and fins, and abdomen mostly naked. The new species is known from the rapids of the rio Culuene, where it is sympatric with Hypostomus faveolus. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon basin; Cascudo; Hypostominae; Rio Culuene; Systematics. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000200003 |
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| Britto,Marcelo R.; Lima,Flávio C. T.; Santos,Alexandre C. A.. |
| During a recent ichthyological survey in Chapada Diamantina, Estado da Bahia, Brazil, a new, very distinctive Aspidoras was discovered in tributaries of the upper rio Paraguaçu. The new taxon differs from its congeners mainly in having: a poorly-developed pigmentation pattern, restricted to minute scattered blotches on dorsal region of head and body, but grouped in small, irregular blotches along the lateral body plate junction; four or five caudal vertebra, anterior to compound caudal centrum, with neural and haemal spines placed posteriorly, close to post-zygapophyses; and post-zygapophyses of the precaudal vertebrae without dorsal expansions connected with their respective neural spines. The new species shares with Aspidoras velites dorsolateral body... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Systematics; Aspidoras maculosus; Sand-dwelling; Paedomorphic characters. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000400004 |
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| DoNascimiento,Carlos; Prada-Pedreros,Saúl; Guerrero-Kommritz,Jürgen. |
| A new Trichomycterus is described from a highland tributary of the río Meta (Orinoco basin), along the east flank of Páramo de Cruz Verde, Eastern Cordillera of Colombia. The new species is distinguished from most of its congeners by having a reduced posterior cranial fontanel, restricted to the parieto-supraoccipital, cleithrum pierced by several foramina, and an unique combination of four irregular rows of conic teeth in premaxilla and dentary, 13-14 opercular odontodes, 41-43 interopercular odontodes, 6-7 branchiostegal rays, 40 or 41 free vertebrae, 14-18 ribs, first ray of pectoral fin slightly projected as a short filament, 7-8 branched pectoral-fin rays, dorsal-fin origin at same level of pelvic-fin insertion, anal-fin origin posterior to dorsal-fin... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ituglanis; Río Orinoco basin; Osteology; Trichomycterinae; Trichomycterus cachiraensis. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000400717 |
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| Bichuette,Maria Elina; Trajano,Eleonora. |
| Rhamdia enfurnada, a new troglobitic (exclusively subterranean) catfish, is described from the Gruna do Enfurnado, Serra do Ramalho, southwestern Bahia State, middle São Francisco River basin. It differs from epigean congeners from the São Francisco River basin by the variable eye size, ranging from reduced to externally invisible (bilateral asymmetry in development of eyes is frequently observed), with a conspicuous orbital concavity (orbital diameter varying from 6.4 to 13.6% of head length in R. enfurnada and from 14.5 to 24.4% in the epigean species); by the dark pigmentation reduced due to a decrease in density of melanophores, and also variable. In comparison to other cave species, R. enfurnada presents a low degree of troglomorphism regarding... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Subterranean catfishes; Rhamdia enfurnada; Bahia; São Francisco River basin; Taxonomy. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000400016 |
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| Sarmento-Soares,Luisa Maria; Lazzarotto,Henrique; Py-Daniel,Lucia Rapp; Leitão,Rafael Pereira. |
| ABSTRACT Species of Centromochlus are widely distributed in South America, with records for major basins such as the Amazon and Orinoco, rivers draining the Guiana Shield such as the Essequibo, Courantyne (Corantijn), Coppename, Maroni, and Oyapock, and Brazilian Shield drainages as upper Paraná and São Francisco. In the last four years, three species of Centromochlus have been described, raising the total number of valid species to sixteen. The new species of Centromochlus described herein is diagnosed by having black ground color sharply delimited from a white underside by conspicuous wavy border. The new species is recorded from the Nhamundá, left bank tributary to the lower Amazon that drain from the Brazilian portion of the Guiana Shield. Although... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Doradoidea; Ostariophysi; South America; Systematics; Tatia .. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000400210 |
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| Bertaco,Vinicius A.; Carvalho,Tiago P.. |
| A new characid species, Hyphessobrycon hexastichos, is described from the upper rio Tapajós, Mato Grosso, Brazil. The new species is distinguished from all other Hyphessobrycon species by the presence of black zigzag longitudinal lines between longitudinal rows of scales in the lateral of body, maxilla with 3-5 teeth, i,6 pelvic-fin rays, 18-22 branched anal-fin rays, 4 scale rows above and 3 scale rows below of lateral line, lateral line with 9-13 perforated scales, and 33-35 scales in a longitudinal series. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Neotropical; Amazon basin; Rio Tapajós; Rio Juruena; Central Brazil; Taxonomy. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000300013 |
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| Deprá,Gabriel C.; Kullander,Sven O.; Pavanelli,Carla S.; Graça,Weferson J. da. |
| Geophagus mirabilis, new species, is endemic to the rio Aripuanã drainage upstream from Dardanelos/Andorinhas falls. The new species is distinguished from all other species of the genus by the presence of one to five large black spots arranged longitudinally along the middle of the flank, in addition to the black midlateral spot that is characteristic of species in the genus and by a pattern of iridescent spots and lines on the head in living specimens. It is further distinguished from all congeneric species, except G. camopiensisand G. crocatus, by the presence of seven (vs. eight or more) scale rows in the circumpeduncular series below the lateral line (7 in G. crocatus; 7-9 in G. camopiensis). Including the new species, five cichlids and 11 fish species... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000400737 |
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| Registros recuperados: 1.204 | |
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