Secondary Sexual Characters
Mostrando 1-12 de 17 artigos, teses e dissertações.
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1. Morphology and biometry of the reproductive organs of adult males of Trachemys scripta elegans reared in São Paulo state, Brazil
RESUMO: Trachemys scripta elegans é um quelônio subaquático americano ilegalmente comercializado em pet shops brasileiros. Ao ser abandonado na natureza, compromete as espécies nativas, ameaçando à biodiversidade local. No entanto, pouco se conhece sobre o desenvolvimento corporal e a estrutura do seu aparelho reprodutor. O objetivo do presente trabalh
Pesq. Vet. Bras.. Publicado em: 30/09/2019
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2. New records of intersexuality in porcelain crabs (Crustacea: Decapoda: Anomura: Porcellanidae)
Abstract The occurrence of intersex specimens of Lissoporcellana quadrilobata (Miers, 1884), Pisidia bluteli (Risso, 1816) and Pisidia longimana (Risso, 1816) is recorded for the first time and their secondary sexual characters analyzed. Intersex specimens were collected in regions regularly affected by pollution. There is a high possibility that intersexual
Nauplius. Publicado em: 26/03/2018
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3. Intersexuality in the porcellanid crab Pisidia longicornis (Crustacea: Decapoda: Anomura: Porcellanidae)
Intersex specimens of Pisidia longicornis (Linnaeus, 1767) are recorded for the first time and their secondary sexual characters are analyzed. Of 145 specimens of P. longicornis examined in this study, six were identified as intersex individuals. Of these, three presented male secondary sexual characters, well-developed male gonopores and rudimentary female
Zoologia (Curitiba). Publicado em: 2015-04
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4. História natural de Benthana cairensis (Isopoda: Oniscidea)
A subordem Oniscidea abriga os isópodos terrestres, os quais apresentam uma grande riqueza de espécies em diferentes ambientes com características completamente diversas, desde a zona litorânea até ambientes desérticos. No Brasil há uma diversidade de espécies ainda pouco estudada, sendo que a família Philosciidae representa uma grande parte da faun
Publicado em: 2010
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5. A connection between extracellular matrix and hormonal signals during the development of the human fetal adrenal gland
The human adrenal cortex, involved in adaptive responses to stress, body homeostasis and secondary sexual characters, emerges from a tightly regulated development of a zone-specific secretion pattern during fetal life. Its development during fetal life is critical for the well being of pregnancy, the initiation of delivery, and even for an adequate adaptatio
Brazilian Journal of Medical and Biological Research. Publicado em: 2005-10
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6. Desenvolvimento juvenil de Hepatus pudibundus (Herbst) (Crustacea, Decapoda, Calappidae), em laboratório
The Hepatus pudibundus (Herbst, 1785) juvenile development was studied in laboratory, under the morphological and systematical stand points. The eight early juvenile stages were obtained from larvae hatched from eggs of two ovigerous females, collected at the northern coast of the State of São Paulo, Brazil. The experiments were carried out in a climaticall
Revista Brasileira de Zoologia. Publicado em: 2003-09
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7. Desenvolvimento juvenil de Cyrtograpsus angulatus Dana (Crustacea, Decapoda, Grapsidae), em laboratório
This paper describes the first nine juvenile stages of Cyrtograpsus angulatus Dana, 1851 obtained in laboratory conditions from three ovigerous females collected at "Molhes da Barra", Rio Grande, Brazil (32ºS and 52ºW). The main morphological features, the secondary sexual characters and the gills ontogeny were observed. Twenty one individuals reached unti
Revista Brasileira de Zoologia. Publicado em: 2000-06
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8. Sexual selection in plants: pros and cons.
Sexual selection has long been regarded as a special mode of selection in animals. Various authors have argued in a growing number of publications since 1979 that sexual selection is also operative in plants, and consequently, two divergent concepts of sexual selection are now being stated in the literature, the original Darwinian concept and the new plant-c
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9. Change in male secondary sexual characters in artificial interspecific hybrid populations.
The interfertile Hawaiian species Drosophila silvestris and Drosophila heteroneura were hybridized, forming reciprocal populations; the SH hybrid line was begun with D. silvestris female parents, and the HS hybrid line was begun with D. heteroneura female parents. Mass laboratory cultures were maintained for 14 generations without artificial selection. The s
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10. Models of speciation by sexual selection on polygenic traits
The joint evolution of female mating preferences and secondary sexual characters of males is modeled for polygamous species in which males provide only genetic material to the next generation and females have many potential mates to choose among. Despite stabilizing natural selection on males, various types of mating preferences may create a runaway process
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11. Genetic biases for showy males: Are some genetic systems especially conducive to sexual selection?
Male secondary sexual characters (conspicuous ornaments, signals, colors) are among nature's most striking features. Yet, it is unclear why certain groups of organisms are more likely than others to evolve these traits. One explanation for such taxonomic biases is that some genetic systems may be especially conducive to sexual selection. Here, we present the
The National Academy of Sciences.
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12. The contagion indicator hypothesis for parasite-mediated sexual selection.
Hamilton and Zuk [Hamilton, W. D. & Zuk, M. (1982) Science 218, 384-387] proposed that females choosing mates based on the degree of expression of male characters obtain heritable parasite resistance for their offspring. Alternatively, the "contagion indicator" hypothesis posits that females choose mates based on the degree of expression of male characters b