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| Registros recuperados: 11 | |
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| Broquard, Coralie. |
| Knowledge about the mode of reproduction and the sex determination of the cupped oyster Crassostrea gigas remains limited. As a sequential hermaphroditic species, sex determination takes place several times during its lifetime. As part of this thesis, the sexual phenotypes of the first 6 years of life of oysters were identified in two cohorts. Thus, the sex ratio was biased towards females from the first sexual maturity, as well as for all subsequent years. After six years of sexing, 42%, 32%, 19%, 5%, 1% and 0.1% of oysters showed 0, 1, 2, 2, 3, 4 and 5 sex changes. The frequency of sex changes also decreased with age (34% between years 1-2 to 9% between years 5-6). This thesis work has also sought to determine the influence of sex and sex change on the... |
| Tipo: Text |
Palavras-chave: Déterminisme sexuel; Facteurs moléculaires; Sex determination; Hermaphroditism; Growth; Molecular factors; C. gigas. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00692/80422/83558.pdf |
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| Broquard, Coralie; Martinez, Anne-sophie; Maurouard, Elise; Lamy, Jean-baptiste; Dégremont, Lionel. |
| Understanding sex determination in the Pacific oyster Crassostrea gigas, a sequential hermaphrodite, can provide prospective on the evolution of sex-determining systems for comparative reproduction from an evolutionary perspective. Surprisingly, this mechanism is still poorly understood. To date, sex ratio and sex change have never been studied at the individual level for a large size group and long-term monitoring. To this purpose, we performed an ambitious individual long-term follow-up (6 years) on a large population (cohort 1: 7488 oysters) produced from wild oysters, as well as for a second population produced from the cohort 1 (cohort 2: 4320 oysters). All oysters were individually sexed from 2014 to 2019. For the cohort 1, our results showed a... |
| Tipo: Text |
Palavras-chave: Sex-ratio; Sex change; Oysters; Hermaphroditism; Crassostrea gigas. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00587/69868/67845.pdf |
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| Roede, Machteld J.. |
| A brief survey is given of current literature in comparison with former studies. Since the 18th century phenotypic diversity of Labridae is a matter of argument. At first in dribs and drabs, yet last decades at a rapid rate, dichromatic adult morphs are synonymized. There are few monochromatic species. Wrasses are protogynous hermaphrodites. Most species are described as monandric, but a minority (of slightly or extremely dichromatic) species is diandric, with both primary and secondary males. Terminal males reproduce with single females, but initial phase males spawn in aggregations. Some species are haremic, and large males are permanently or temporarily territorial. Last decades insight in the various social factors has greatly increased, resulting in... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Sex reversal; Hermaphroditism; Diandry; Monandry; Sex dimorphism; Color changes; Sexual behavior; Labridae. |
| Ano: 1990 |
URL: http://www.repository.naturalis.nl/record/504233 |
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| Calvo, J.; Morriconi, E.; Orler, P.. |
| The theoretical aspects of reproductive strategies and life histories are analyzed. The gonadal structures and the main features of gametogenesis of bivalves and echinoids are described. Research on the reproductive characteristics and gametogenic cycles of the bivalve molluscs in the Argentinian littoral and the echinoid Loxechinus albus is reviewed. Special references to Mytilus edulis, Aulacomya ater, Brachidontes purpuratus, Aequipecten tehuelchus, Zygochlamys patagonica, Ostrea puelchana, Clausinella gayi, Protothaca antiqua, Eurhomalea exalbida and Mesodesma mactroides are made. Analysis of reproductive cycles includes histological and ponderal descriptions of gonadal variations. The main trend found is the partial and multiple spawning episodes.... |
| Tipo: Book Section |
Palavras-chave: Hermaphroditism; Gametogenesis; Life cycle; Marine molluscs; Reproduction; Reproductive cycle; Hermaphroditism; Gametogenesis; Life cycle; Reproduction; Http://aims.fao.org/aos/agrovoc/c_3571; Http://aims.fao.org/aos/agrovoc/c_27931; Http://aims.fao.org/aos/agrovoc/c_4317; Http://aims.fao.org/aos/agrovoc/c_6507. |
| Ano: 1998 |
URL: http://hdl.handle.net/1834/2581 |
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| Manjarrés Villamil, Alex E.; Lucero Rincón, Carlos H.; Walteros, William O.; Kantera Kintz, Jaime R.; Gil Agudelo, Diego L.. |
| La abundancia y madurez sexual de la piangua Anadara similis fue analizada mensualmente entre septiembre de 2009 y agosto de 2010 en el archipiélago de La Plata, Bahía Málaga, Pacífico colombiano. La madurez sexual se analizó a nivel macroscópico mediante la observación del tejido reproductivo en fresco y microscópico por medio de métodos histológicos estándares. Se estimó una densidad media de 0.130 ± 0.098 ind/m2 y una talla media de 42.30 ± 5.00 mm. Los meses de mayor densidad fueron mayo (0.295 ind/m2) y agosto (0.195 ind/m2). La talla media de madurez sexual fue de 41.8 ± 4.5 mm y talla media de 41 mm donde 50% de la población ha tenido mínimo un desove (L50%). Se registraron picos máximos reproductivos durante marzo (83.3%) y abril (75.0%), aunque... |
| Tipo: Journal Contribution |
Palavras-chave: Density; Hermaphroditism. |
| Ano: 2013 |
URL: http://hdl.handle.net/1834/5454 |
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| Registros recuperados: 11 | |
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