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| Registros recuperados: 70 | |
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| Ochoa,Luz E.; Melo,Bruno F.; García-Melo,Jorge E.; Maldonado-Ocampo,Javier A.; Souza,Camila S.; Albornoz-Garzón,Juan G.; Conde-Saldaña,Cristhian C.; Villa-Navarro,Francisco; Ortega-Lara,Armando; Oliveira,Claudio. |
| ABSTRACT Catfishes of the family Astroblepidae form a group composed by 82 valid species of the genus Astroblepus inhabiting high-gradient streams and rivers throughout tropical portions of the Andean Cordillera. Little has been advanced in the systematics and biodiversity of astroblepids other than an unpublished thesis, a single regional multilocus study and isolated species descriptions. Here, we examined 208 specimens of Astroblepus that apparently belong to 16 valid species from several piedmont rivers from northern Colombia to southern Peru. Using three single-locus approaches for species delimitation in combination with a species tree analysis estimated from three mitochondrial genes, we identified a total of 25 well-delimited lineages including... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Andes; Catfishes; Delimitation; Ostariophysi; Systematics; Taxonomy. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000400205 |
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| Quagio-Grassiotto,Irani; Gameiro,Maria Carolina; Schneider,Tatiana; Malabarba,Luiz Roberto; Oliveira,Claudio. |
| Spermiogenesis in the curimatid species, Steindachnerina insculpta, Cyphocharax gillii, C. modestus, C. spilotus, and Potamorhina altamazonica, is characterized by lateral development of the flagellum, nuclear rotation, eccentric nuclear fossa formation, and chromatin compacted into thick fibers. These spermatozoa exhibit a spherical head containing a nucleus with the chromatin highly condensed into thick fibers with small electron-lucent areas, and no acrosome. The nuclear fossa is of the moderate type and eccentric and penetrated by the centriolar complex. The midpiece is small, has many elongate vesicles, and a short cytoplasmic channel. Mitochondria may be elongate, branched or C-shaped, and are separated from the initial segment of the axoneme by the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Spermatid; Sperm; Ultrastructure. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252003000100004 |
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| Gusmão-Pompiani,Priscila; Malabarba,Luiz R.; Oliveira,Claudio; Quagio-Grassiotto,Irani. |
| Spermatozoa and spermiogenesis ultrastructure were studied in the serrasalmine species Piaractus mesopotamicus, Mylossoma duriventre, Serrasalmus maculatus, and Metynnis mola and two distinct patterns may be recognized: the first common to Mylossoma, Serrasalmus and Metynnis, and the other, characteristic of Piaractus. The latter pattern is more similar to the conditions found in Salminus and Brycon. On the other hand, serrasalmine spermatozoa also share characteristics with the spermatozoa of species of the superfamily Anostomoidea. The phylogenetic significance of these characters is discussed. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Characid; Spermatid; Spermatozoa; Phylogeny; Morphology. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000300005 |
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| Alves,Anderson Luis; Porto-Foresti,Fábio; Oliveira,Claudio; Foresti,Fausto. |
| Cytogenetic analyses carried out in eight specimens of Sphoeroides spengleri revealed the presence of 2n = 46 chromosomes (20 M/SM and 26 ST/A). Besides the standard karyotypical set, the presence of B microchromosomes was observed in two individuals, ranging from 0 to 2 microchromosomes per cell. A karyotype composed by 2n = 46 chromosomes with occurrence of M and SM chromosomes is considered basal for the species from the clade comprising the families Tetraodontidae, Balistidae, and Diodontidae, although it represents a derived condition for the order Tetraodontiformes, whose basal karyotype would be composed by 2n = 48 acrocentric chromosomes. The occurrence of B microchromosomes in marine Tetraodontiformes fish was not known, and this represents the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: B chromosome; Pufferfish; Sphoeroides spengleri. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200014 |
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| Maistro,Edson Luis; Oliveira,Claudio; Foresti,Fausto. |
| Among four specimens of Astyanax scabripinnis sympatrically collected from the Tamanduá stream (State of São Paulo, Brazil), three, named cytotype I, had 2n = 50 chromosomes (6M + 26SM + 4ST + 14A) and a fundamental number (FN) of 86, and one specimen, named cytotype II, had 2n = 48 chromosomes (6M + 28SM + 4ST + 10A) and FN = 86. Besides the difference in diploid number, the cytotypes showed a clear difference in the distribution of constitutive heterochromatin. One NOR-bearing chromosome pair was detected in both cytotypes and one specimen of cytotype I had multiple NORs (tree chromosome pairs). Robertsonian translocations and an increase or loss of heterochromatin are proposed to explain the karyotypic divergence observed. Some aspects related to the... |
| Tipo: Info:eu-repo/semantics/other |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000200021 |
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| Marceniuk,Alexandre Pires; Rotundo,Matheus Marcos; Caires,Rodrigo Antunes; Cordeiro,Ana Patricia Barros; Wosiacki,Wolmar Benjamin; Oliveira,Claudio; Souza-Serra,Rayla Roberta Maganhães de; Romão-Júnior,João Gomes; Santos,Wagner César Rosa dos; Reis,Thayson da Silva; Muniz,Mairink Ribeiro; Cardoso,Gustavo Stabile; Ferrari,Stephen; Klautau,Alex Garcia Cavalleiro de Macedo; Montag,Luciano. |
| ABSTRACT The Brazilian North coast is one of the world’s most important shrimp fishery grounds, with a total area of approximately 223,000 km2. However, the available data on the diversity of fish caught by the region’s industrial trawler fleet are limited to the commercially-valuable species. This lacuna in the data on the region’s marine fish fauna is worrying, both for the management of stocks and the conservation of the local biodiversity. The present study was based on a comprehensive inventory of the teleost fishes captured by the industrial outrigger trawling operations off the North coast of Brazil. This inventory recorded 201 species belonging to 64 families and 20 orders, and revealed a unique fauna, characterized by 17 endemic species, and a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biodiversity; Bycatch; Fishes discarded; Inventory; Marine fish; Outrigger trawling. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000200205 |
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| Melo,Bruno F.; Sato,Yoshimi; Foresti,Fausto; Oliveira,Claudio. |
| The rio São Francisco basin contains many endemic species, such as Prochilodus argenteus and P. costatus, which have great commercial importance. However, information about the main recruitment sites and genetic studies containing extensive sampling of these species are scarce. To investigate the roles of the marginal lagoons in the maintenance of genetic variability and in the population structure, we analyzed six microsatellite loci in nine sampling groups of P. argenteusand five sampling groups of P. costatus. Our results showed high levels of genetic variability and low values of genetic differentiation for P. argenteus (FST =0.008, P< 0.05) and for P. costatus(FST =0.031, P < 0.05). In addition, high values of gene flow combined with a small... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conservation genetics; Fish migration; Microsatellite; Nursery area; Rio São Francisco basin. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000300625 |
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| Spadella,Maria A.; Desan,Simone P.; Henriques,Teresa C. B. P. O.; Oliveira,Claudio. |
| ABSTRACT Callichthyidae comprises a well-corroborated monophyletic group divided into two subfamilies: Corydoradinae and Callichthyinae. A recent proposal, based on molecular data, suggests that Corydoradinae is composed by nine monophyletic lineages, possibly genera. The species pertaining to those lineages have extensive modification in the size of genome, including diploid, tetraploid and octoploid species. Considering the occurrence of these monophyletic lineages and that the variations in DNA content may imply in significant alterations on the structure of spermatozoa, this study analyzed the morphology of the male reproductive system and the morphometry of the head of the spermatozoa of representatives of the nine lineages of Corydoradinae, seeking... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Monophyly; Morphometry; Spermatozoa; Variations in DNA. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000100221 |
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| Registros recuperados: 70 | |
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