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| Registros recuperados: 10 | |
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| Valentim,Francisco Carlos de Souza; Porto,Jorge Ivan Rebelo; Feldberg,Eliana. |
| Abstract Cytogenetic studies in the subfamily Potamotrygoninae have provided valuable insights into the understanding of the evolution and diversification of its species. In the present study, the chromosomal features of seven nominal potamotrygonin species are provided: Plesiotrygon iwamae (2n=74, FN=120), Potamotrygon amazona (2n=66, FN=107), P. constellata (2n=66, FN=110), P. leopoldi (2n=64, FN=102), P. motoro (2n=66, FN=106) from four different localities, and P. orbignyi (2n=66, FN=106), P. scobina (2n=66, FN=104), from Central Amazon. Additionally, we found a new karyomorph in P. wallacei. We considered the localization of Nucleolus Organizer Regions (NORs), as well as the pattern of constitutive heterochromatin, as species-specific characters. We... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Elasmobranchs; Cytogenetics; Chromosomal rearrangements; Sex chromosomes; Karyotypic diversity. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000400578 |
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| Schmid,Kurt; Andrade,Marcelo; Machado,Fabiola; Araujo,Juliana; Corrêa,Eglé; Giarrizzo,Tommaso. |
| Abstract: A Longnose stingray Hypanus guttatus (Bloch & Schneider, 1801) embryo with a major asymmetrical morphological abnormality to its pectoral fin was obtained from commercial shrimp fisher's bycatch, off the coast of the Amazon River Mouth in northern Brazil. The specimen and the deformity, which would presumably have impeded its long-term survival, are described and documented in detail. We herein provide the first report of an abnormal individual of this species for the Brazilian coast. |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Fish; Elasmobranchs; Atlantic; Teratology; Deformity. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032019000400502 |
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| Rêgo,Mariana G.; Hazin,Fábio H. V.; Evêncio Neto,Joaquim; Oliveira,P. G. V.; Soares,Maria Goretti; Torres,Keilla Regina L. S.; Lana,Fernanda O.; Roque,Pollyana C. G.; Santos,Natália L.; Coelho,Rui. |
| This work aims to study the female reproductive tract of silky sharks, Carcharhinus falciformis, captured in the South and Equatorial Atlantic Ocean. Samples were collected between January 2008 and March 2010 through oceanic commercial vessels that targeted tuna and swordfish, with a total of 17 females collected. The methodologies followed for analyzing the ovaries of those females included both macroscopic and histological analysis. Macroscopically, it was possible to determine that the ovaries on these sharks is suspended by mesenteries in the anterior section of the body cavity, heavily irrigated by blood vessels, and contains a wide range of oocytes. Ovaries were found in three distinct maturational stages: Stage I (Immature), Stage II (Maturing) and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Elasmobranchs; Histology; Maturity; Ovary; Reproduction. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000400815 |
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| Wehitt,Anahí; Di Giacomo,Edgardo E; Galíndez,Elena J. |
| Chondrichthyans are extremely susceptible to overfishing due, among other things, to their reproductive adaptations. Basic knowledge of reproductive parameters is essential, both of ecological and for economic points of view. Zearaja chilensis is a valuable economic resource in South America. This work analyzes the microanatomy of female reproductive system, as well as the size of the onset of vitellogenesis. The material was fixed in Bouin and processed using routine histological techniques. Both ovaries are equally functional. Folliculogenesis depicts the same pattern of other Chondrichthyans. Follicles with different degrees of maturation coexist in mature animals, with the exception of oogonia, which were only found in immature individuals. Likewise,... |
| Tipo: Journal article |
Palavras-chave: Elasmobranchs; Reproductive system; Ovary; Zearaja chilensis. |
| Ano: 2015 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022015000100049 |
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| Gonzalez,Manoel M. B.. |
| Artifacts made from rays (rostral teeth and spine) are very common in shell mounds on the coast of São Paulo, Brazil. The presence of the genus Pristis among the studied species of elasmobranch fishes in this shell mounds reinforces the hypothesis these animals occurred in southeastern Brazil, and were used by hunter-gatherers. I analyzed twelve rostral teeth of the genus Pristis from shell mounds. The teeth have artificial marks left from making arrows and harpoons. The basic function of the teeth found in these shell mounds was the production of tools and ornaments. From the analyzed teeth, ten (83%) were associated to the faunal remain and two (17%) were associated with burials, and they can be considered as ceremonial or votive elements. There had been... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sawfish; Elasmobranchs; Shell mounds; Zooarchaeology; Human ecology. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000300010 |
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| Registros recuperados: 10 | |
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