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| Registros recuperados: 33 | |
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| Menezes,Naércio A.; Weitzman,Stanley H.. |
| Diapoma is reviewed and four species are recognized: (1) Diapoma thauma, new species, from streams of the rio Jacuí basin, state of Rio Grande do Sul; (2) D. pyrrhopteryx, new species collected from the rio Canoas and streams flowing into this basin in the states of Rio Grande do Sul and Santa Catarina, Brazil; (3) Diapoma terofali, from streams flowing into rio Uruguay in Uruguay and Rio Grande do Sul, Brazil and streams flowing into rio de la Plata, Argentina; and (4) Diapoma speculiferum, from lowland coastal streams in Rio Grande do Sul, Brazil and Uruguay. Diapoma pyrrhopteryx possess the posteroventral opercular elongation typical of D. speculiferum, type species of the genus, but which is absent in D. thauma and D. terofali. Nonetheless, all the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Taxonomy; New species; Characidae; Diapoma. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492011000500001 |
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| Zanata,Angela M.; Camelier,Priscila. |
| Two new Astyanax species, A. vermilion, from rio Almada and rio Cachoeira, and A. burgerai, from rio Almada, Bahia State, Brazil, are described. Astyanax vermilion is distinguished from most of its congeners and from all other Astyanax species known from northeastern Brazilian drainages by having distal portion of pelvic fins dark, a combination of sexually dimorphic characters, posteroventral portion of body and fins (except pectoral) reddish in life, and inconspicuous humeral and caudal spots. It also differs by having highest body depth just anterior of dorsal-fin origin, 32-34 lateral-line scales, and presence of one or two maxillary teeth. Astyanax burgerai is diagnosed by the presence of two vertically elongated humeral blotches, absence of a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: New species; Sexual dimorphism; Coastal drainages; Characidae. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000200007 |
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| Veregue,Angela Maria Louzada; Orsi,Mário Luís. |
| Some aspects of the reproductive cycle of female "lambari", Astyanax scabripinnis paranae (Eigenmann, 1927) were studied. The specimens were collected in intervals of fifteen days, from September 1979, until November 1980, in the Marrecas creek (Irerê and Paiquerê districts), Londrina, Paraná, Brazil. The maturity scale was characterized in five stages: immature, maturation, spawning, spent, and resting, which was established by the gonad-somatic relation and the ovary morphology and microscopic aspects. The maturation curve and distribution of maturity stages show that the period of reproduction is very long; spawning extended from July to March. The gonad cycle is related to seasons: maturation occurs chiefly in the winter months, spawning specimens are... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Astyanax scabripinnis; Characidae; Biology; Reproduction; Tibagi river. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752003000100012 |
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| Graça, Weferson Júnio da; UEM; Pavanelli, Carla Simone; UEM. |
| Garutti (1995) fez a revisão de algumas espécies de Astyanax (Osteichthyes, Characidae) e aquela, conhecida como “tambiú” na bacia do alto rio Paraná, anteriormente identificada como Astyanax bimaculatus, foi considerada nova e posteriormente descrita por Garutti & Britski (2000) como Astyanax altiparanae (Pisces, Characiformes). Naquela oportunidade, entretanto, não foram analisados exemplares da bacia do rio Iguaçu. Esse afluente do rio Paraná apresenta um alto grau de endemismo em sua ictiofauna devido ao isolamento geográfico causado pelas cataratas situadas próximo à sua foz. No entanto, muitas dúvidas relacionadas ao status específico da população da bacia do Iguaçu, também chamada de A. bimaculatus antes dos trabalhos de Garutti, permaneceram.... |
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Palavras-chave: 2.00.00.00-6 Ciências Biológicas Astyanax altiparanae; Distribuição geográfica; Rio Iguaçu; Bacia do alto rio Paraná; Characidae; Tetragonopterinae 2.00.00.00-6 Ciências Biológicas. |
| Ano: 2002 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/2319 |
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| Pedreira, Marcelo Mattos; UFVJM; Sampaio, Edson Vieira; CODEVASF - Três Marias; Santos, José Cláudio Epaminondas dos; CODEVASF - Três Marias; Luz, Ronald Kennedy; UFMG. |
| O presente experimento avaliou o desempenho e sobrevivência de juvenis de matrinxã Brycon orthotaenia cultivados em tanques-rede de 4 m3, por 197 dias, em três densidades de estocagem: 20, 40 e 60 peixes m-3. Foram utilizados exemplares com 19,9 ± 0,3 cm de comprimento total e 90,0 ± 0,15 g de peso. Os animais foram alimentados com ração extrusada contendo 36% de proteína bruta. O comprimento total e o peso foram superiores (p < 0,05) na densidade de 20 peixes m-3. Valores intermediários e inferiores foram registrados para a densidade de 40 e 60 peixes m-3, respectivamente. A sobrevivência e o Fator de condição de Fulton foram semelhantes (p > 0,05) entre as diferentes densidades; porém, a biomassa produzida foi superior (p < 0,05)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 2.00.00.00-6 Ciências Biológicas rio São Francisco; Characidae; Tanques-rede; Espécie neotropical; Matrinxã 5.06.03.00-0 São Francisco river; Characidae; Floating Cage; Neotropical fish; Matrinxã. |
| Ano: 2009 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/3687 |
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| Nunes,Daniela M.; Pellanda,Mateus; Hartz,Sandra Maria. |
| Oligosarcus jenynsii (Günther, 1864) and O. robustus Menezes, 1969 are fish species distributed in Rio Grande do Sul, Brazil, Uruguay, and northern Argentina. The reproductive period and recruitment, sex ratio, absolute and relative fecundity, and body length at first gonadal maturation of the two carnivorous species from Fortaleza Lagoon were analized. The specimens were sampled monthly, from May 2000 to April 2001, with fishing effort of 24 hours/month, using stationary gillnets of different mesh sizes and seine net (three samples per edge). The records of each individual included total length, total weight, gonad weight, sex and gonadal maturity stage. The reproductive period of both O. jenynsii and O. robustus ranges from May/June to November/December,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oligosarcus; Reproduction; Characidae; Southern Brazil. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212004000100001 |
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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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| Bem,Jaqueline Cristina de; Fontanetti,Carmem Silvia; Senhorini,José Augusto; Parise-Maltempi,Patricia Pasquali. |
| The objective of this study was to evaluate the effectiveness of estradiol valerate in an attempt to feminize the male Astyanax altiparanae. One thousand newly-hatched larvae were randomly distributed in four incubators. During a period of 30 days, estradiol valerate was administered in different dosages (20, 40, and 80 mg/kg of diet); the control group did not receive hormone in the diet. After 161 days of hatching, biometry was performed on 50 fishes per treatment group, and the gonads were analyzed. The hormone treatments were effective in feminizing A. altiparanae, achieving 70-76% of the desired sex, while the control treatment had 44% females. The hormone did not affect the growth of fish. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Astyanax altiparanae; Characidae; Feminization; Sex Reversion; Estrogen. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000200015 |
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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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| Hahn,Norma Segatti; Delariva,Rosilene Luciana; Loureiro,Valdirene Esgarbosa. |
| With objective to know feeding spectrum of Acestrorhynchus lacustris (Reinhardt, 1874), a middle size predator in different places of influence area of Itaipu reservoir, stomach contents were analyzed. Samples were collected from March 1984 to February 1989 from Itaipu Reservoir and its adjacent areas. Its fed mainly on fishes, but it was an opportunistic (consumed 17 species of prey). Despite of the wide feeding spectrum, few preys were dominant in the diet, according to the different habitats sampled. As a result, it significant spatial differences in the diet was observed. Was observed through "Detrented Correspondence Analysis" (DCA) these were divided into three groups in relation with diet: preys from upstream, with higher scores; preys from the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Feeding; Predation; Characidae; Upper Paraná River; Itaipu Reservoir. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132000000200010 |
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| Cavalheiro,Laísa Wociechoski; Fialho,Clarice Bernhardt. |
| Abstract: The ichthyofauna of streams in the Neotropical region is not yet fully known. This study aims to investigate the ichthyofauna composition of six streams of the Ijuí River sub-basin, Rio Grande do Sul State, inserted in the Uruguay River basin, as to contribute to the knowledge of fishes species richness and distribution in the south of Brazil. Sampling was carried out between July 2015 and May 2016, bimonthly, using the technique of electric fishing to collect the fishes. Spatial variations (per sampled stream) in the ichthyofauna composition were tested with a permutational multivariate analysis of variance. In total, we collected 5,029 individuals from 55 species, 13 families and five orders. From these species, 17 are endemic to the Uruguay... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Abundance; Characidae; Heptapteridae; Loricariidae; Richness; Uruguay River basin. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032020000100302 |
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| Nunes,Lucas T.; Morais,Renato A.; Longo,Guilherme O.; Sabino,José; Floeter,Sergio R.. |
| ABSTRACT Species interactions can modulate the diversity and enhance the stability of biological communities in aquatic ecosystems. Despite previous efforts to describe fish interactions in tropical rivers, the role of habitat characteristics, community structure, and trophic traits over these interactions is still poorly understood. To investigate among-habitat variation in substratum feeding pressure and agonistic interactions between fishes, we used remote underwater videos in three habitats of a clearwater river in the Central Western, Brazil. We also performed visual surveys to estimate the abundance and biomass of fishes and proposed a trophic classification to understand how these variables can affect fish interactions. Community structure was the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bodoquena plateau; Centrality; Characidae; Feeding pressure; Habitat heterogeneity. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000100217 |
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| Chehade,Chayrra; Cassel,Mônica; Borella,Maria Inês. |
| Captive reproduction is one of the problems faced in aquaculture requiring the manipulation of environmental factors and/or hormonal treatment. Thus, we seek to verify experimentally which gonadal changes were present in mature individuals of Astyanax altiparanae arising from decreased water level. Collections were made every four hours, initiated four hours before and finished 28 hours after stimulation, at the Fish Farming Station of Companhia Energética de São Paulo, São Paulo, Brazil. The gonads were analyzed by light microscopy. The females had ovaries in the spawning capable phase until 12h; in 16h, in a more advanced stage of spawning capable phase; and, from 20h, in the regressing phase. Males had testes in the spawning capable phase until 8h; in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Asynchronous reproduction; Characidae; Gametogenesis; Gonadosomatic index; Histology. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000100205 |
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| Registros recuperados: 33 | |
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