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Registros recuperados: 37 | |
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Nielsen,Jørgen G.; Mincarone,Michael M.; Di Dario,Fabio. |
A new species of Barathronus (Ophidiiformes: Aphyonidae) is described from a single, mature male specimen (101 mm SL) bottom trawled on the continental slope of Rio Grande do Norte, northeastern Brazil, between 1,964 and 2,045 m depth. The new species is diagnosed among congeners by the following combination of characters: peritoneum transparent, deep-set eyes not visible, eight fangs on vomer, anal fin rays 69, predorsal length 42.0% SL, preanal length 49.5% SL, penis long, slender, and lacking a pair of lobes at its base, and presence of a ventral flexure of the anterior 2-3 vertebrae. Additionally, morphological data of three specimens of Barathronus bicolor collected in Brazilian waters are presented and compared with those from 51 specimens from the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Teleostei; Deep-sea diversity; Potiguar Basin; Western South Atlantic; Brazilian EEZ. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000100053 |
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Calegari,Bárbara B.; Reis,Roberto E.. |
Microlepidogaster longicolla, new species, is described from the rio São João of the upper rio Paraná basin near Brasília, in central Brazil. The new species differs from M. perforatus, the only other species in this genus, by having a continuous lateral line, median lateral plate series reaching, rather than falling short of, the end of the caudal peduncle, a shorter pectoral-fin spine (13.4-16.2 vs. 18.2-21.0% standard length), a smaller interorbital distance (38.9-43.1 vs. 47.7-53.3% head length), and more numerous dentary teeth (16-29 vs. 12-15), in addition to several osteological features. Microlepidogaster longicolla shows a remarkable suite of secondary sexually dimorphic characters, involving the presence of a conical urogenital papilla in males,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Teleostei; Neotropical; Taxonomy; Catfish; Cascudinhos. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252010000300007 |
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Calegari,Bárbara B.; Pablo Lehmann,A.; Reis,Roberto E.. |
Otothyropsis piribebuy, new species, is described from the río Piribebuy, a tributary to the río Paraguay basin, Cordillera, Paraguay. The new species is distinguished from O. marapoama mainly by having a continuous mid-dorsal series of 17-18 lateral plates, a robust levator crest in the hyomandibula, naked areas in the abdomen, an unpigmented circular blotch on the median portion of the lower lobe, and by several features related to sexual dimorphism. In addition, Otothyropsis is re-diagnosed and its phylogenetic relationships are discussed based on its present diversity. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cascudinho; Catfish; Neotropical; Systematics; Teleostei. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000200002 |
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Pinna,Mário C. C. de; Kirovsky,Alexandre L.. |
A new species of sand-dwelling catfish genus Pygidianops, P. amphioxus, is described from the Negro and lower Amazon basins. The new species differs from its three congeners in the elongate eel-like body, the short barbels, and the small caudal fin, continuous with the body, among other traits of internal anatomy. The absence of anal fin further distinguishes P. amphioxus from all other Pygidianops species except P. magoi and the presence of eyes from all except P. cuao. The new Pygidianops seems to be the sister species to P. magoi, the two species sharing a unique mesethmoid with a dorsally-bent tip lacking cornua, and a produced articular process in the palatine for the articulation with the neurocranium. Pygidianops amphioxus is a permanent and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biodiversity; Freshwater; Psammophyly; Systematics; Teleostei. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000300004 |
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JIMÉNEZ-PRADO,Pedro; VASQUEZ,Fernando. |
RESUMEN La interpretación de la diversidad biológica puede resultar muy compleja, ya que existe una dinámica basada en el origen y en la diversificación de las especies, así como en los efectos antrópicos, tales como la introducción de especies invasoras, cuya consecuencia puede conducir a la extinción local de especies nativas. El objetivo de este trabajo fue analizar la variación temporal (2012 y 2017), tanto en composición como en distribución de la ictiofauna a lo largo del río Atacames, noroccidente del Ecuador. En 2012 se registró: 1) la presencia de Astyanax ruberrimus que se extinguió localmente para el 2017; y 2) la presencia de la tilapia (Orechromis niloticus) como única especie introducida a la que se sumó el guppy (Poecilia gillii) para el... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biodiversidad; Ecología acuática; Neotrópico; Teleostei. |
Ano: 2021 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2021000100081 |
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Diogo,Rui. |
As noted Gould in his recent and last book «The structure of evolutionary theory», discourses on the high importance and frequency of evolutionary trends have consumed a great part of the research on the history of clades. Although aware that natural selection theoretically yields adaptation to immediate environments, many authors defend such trends as generalised improvements somehow conferring advantages across most or all experienced environments. The high importance given to evolutionary trends is questioned by Gould, who considers that such a high importance given to such evolutionary trends bears no necessary relationship to the relative frequency or casual weight of these events in evolution, but mainly to a major bias: trends tell histories, and... |
Tipo: Journal article |
Palavras-chave: Evolution; Morphology; Phylogeny; Siluriformes; Teleostei. |
Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022006000500016 |
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Datovo,Aléssio; Bockmann,Flávio Alicino. |
The skeletal muscles of the dorsolateral region of the head of the Nematogenyidae and representatives of the all major clades of the Trichomycteridae are described and illustrated. A hypothesis on the phylogenetic relationships among these taxa exclusively based on the surveyed musculature is presented. The single most parsimonious cladogram obtained from the phylogenetic analysis of the 36 myological characters gathered and 35 terminal-taxa mostly agrees with the previous hypotheses of trichomycterid intrarelationships. The Copionodontinae and Trichogeninae form a monophyletic lineage that is the sister-group to all remaining trichomycterids. The monophyly of the clades formed by Glanapteryginae plus Sarcoglanidinae; Stegophilinae plus Tridentinae plus... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Myology; Ostariophysi; Teleostei. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252010000200001 |
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Garcia,José Antônio Dias; Chini,Helena A.S.; Maistro,Edson Luis; Quagio-Grassiotto,Irani. |
Oogenesis involves a set of transformations which are undergone by female germ cells These cells change into oogonias and then into mature oocytes. Sexually mature female fish were collected monthly, during one year, from the Sapucaí River, a tributary of the Rio Grande, which is part of the Furnas Reservoir in the state of Minas Gerais. During the several stages of maturation, we observed small round oogonias with a large nucleus, a single nucleolus, and weakly stained cytoplasm with eosinophilic granules. The primary oocytes showed a large basophilic nucleus, with a developed peripheral nucleolus and a reduced cytoplasm. The previtellogenic oocytes presented voluminous cytoplasm and nucleus with several small peripheral nucleoli. The oocytes underwent... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Teleostei; Characidae; Astyanax fasciatus; Oogenesis; Cytochemical. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752001000400003 |
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Chini,Helena A.S.; Garcia,José Antônio Dias; Maistro,Edson Luis; Quagio-Grassiotto,Irani. |
Oogenesis involves a sequense of transformations which are undergone by female germ cells. These cells change into oogonias and then into mature oocytes. Sexually mature females were collected monthly, during one year, from the Rio Sapucaí, tributary of the Rio Grande, which is part of the Furnas Reservoir system in the state of Minas Gerais. The observed material showed that oogonias were small spherical cells, had a big spherical nucleus, with a single nucleolus, and weakly stained cytoplasm with eosinophilic granules (FG stained), which indicate their protein content. The primary oocytes showed a big basophilic nucleus, with a large peripheral nucleolus, and several smaller nucleoli. They show a reduced cytoplasmic content. The previtellogenic oocytes... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Teleostei; Anostomidae; Leporinus striatus; Oogenesis; Cytochemical. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752001000400004 |
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Matos,Edilson; Matos,Patricia; Corral,Laura; Azevedo,Carlos. |
Spermatozoa of amazon fish, Acestrorhynchus falcatus Bloch, 1794 were investigated by optical microscopy (DIC) and electron microscopy (TEM). Spermatozoa have no acrosome, the head is ovoid, and the midpiece region cylindrical, contains spherical mitochondria. The centriolar complex is located at the lateral side of the nucleus, formed by nine peripheral pairs of microtubules and arranged in a right angle to each other. The flagellum consists of nine pairs of peripheral and two central microtubules. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Teleostei; Characidae; Acestrorhynchus falcatus; Ultrastructure; Spermatozoon. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752000000300019 |
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Chaves,Paulo de Tarso C; Vendel,Ana Lúcia. |
The species of Citharichthys Bleeker, 1862, C. arenaceus Evermann & Marsh, 1900 and C. spilopterus Günther, 1862, are the most common flatfishes found in Guaratuba Bay, south Brazil. Different size categories of these flatfish occur in the mangrove area throughout the year. The Gonadosomatic Index, the Condition Factor, and the morphological analyses of the gonads from samples obtained between 1994 and 1996 reveals a spawning activity during late Spring and early Summer. This period coincides with the increase in temperature and decrease in salinity. Spawning evidence and the presence of ali size categories throughout the year indicate that Citharichthys spp. are permanent inhabitants of the mangrove in Guaratuba Bay, where they complete their life... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Teleostei; Pleuronectiformes; Fish reproduction; Guaratuba Bay; Brazil. |
Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751997000100007 |
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Registros recuperados: 37 | |
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