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| Cassel,Mônica; Mehanna,Mahmoud; Mateus,Lúcia; Ferreira,Adelina. |
| The comprehension of the reproductive cycle allows to understand which are the morphological changes that develop in the gonad during this interval. Thus, many studies have been undertaken in order to describe and classify the stages of gonadal development and reproductive status of Neotropical fishes. For this purpose, specimens of Melanorivulusaff. punctatus were collected in a permanent dam in Chapada dos Guimarães, Mato Grosso, Brazil. The gonads were prepared for analysis by light microscopy. The oogenesis and spermatogenesis have been described, characterizing the stages of gonadal development, together with assessments of the gonadosomatic ratio, germ cell count and verification of variation of mature oocytes in females. Throughout the year the male... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gonadossomatic ratio; Histology; Oogenesis; Spermatogenesis. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000100179 |
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| Ferreira,Adelina; Mehanna,Mahmoud; Prado,Cynthia P. A.. |
| The spermatogenesis of Pseudis limellum, from the Southern Pantanal, Brazil, was studied from July 1995 to May 1996, through histological sections of the testis. The cells could be differentiated as: primary spermatogonia, large cells, generally with bilobed nucleus; secondary spermatogonia, smaller cells, with darker cytoplasm, chromatin of radial form; primary and secondary spermatocytes, differentiated according to the different stages of the nucleus during the successive cells divisions. Furthermore, we observed cells in process of morphologic differentiation: rounded spermatids much smaller, with nucleus containing chromatin in compacting process and cytoplasm reduction; elongated spermatids, generally parallel organized in well defined bundles, with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spermatogenesis; Male; Amphibia; Climatic influences. |
| Ano: 2008 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452008000200004 |
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| Ferreira,Adelina; Kihara,Virginia Ojeda; Mehanna,Mahmoud. |
| Reproductive strategy is the set of adaptations that promote the most efficient way that the species will survive under the particular conditions of a determined environment. Understanding these adaptations is important and can help pinpoint populations indicator of environmental changes. Spermatogenesis is a measurable biological process of these adaptations in spatial and temporal scales. We analyzed the morphology of the testes and oviducts of the lizard species that comprise the genus Tropidurus, taking into account the geographical distribution and sympatric relations. For the analysis and the testes were removed from the middle part of the oviducts from Tropidurus etheridge, T. oreadicus, T. itambere, T. spinulosus and T. Guarani species, collected... |
| Tipo: Journal article |
Palavras-chave: Reproductive cycle; Lizards; Brazil. |
| Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022011000400058 |
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