Consulta: subjectFacets:"Reproductive effort"
Registros recuperados: 13
Data/hora: 10/06/2024 10:07:52

Biomass Partitioning Following Defoliation of Annual and Perennial Mediterranean Grasses
Provedor de dados: 7
Autores: Gutman, Mario; Agricultural Research Organization; mgutman@shani.net; Noy-Meir, Imanuel; Hebrew University of Jerusalem; noymeir@agri.huji.ac.il; Pluda, Daniel C; Volcani Center;; Seligman, No'am; Volcani Center; noamseli@netvision.net.il; Rothman, Steven; ;; Sternberg, Marcelo; Tel Aviv University; MarceloS@tauex.tau.ac.il.
A two-year experiment was conducted in northeastern Israel to study the effects of various defoliation regimes on biomass partitioning between vegetative and reproductive structures in a perennial and an annual Mediterranean grass. Greater insight into the mechanisms regulating biomass partitioning after defoliation enables ecologists and rangeland managers to interpret and predict population and community dynamics in Mediterranean grasslands more efficiently. Two typical Mediterranean grasses, Triticum dicoccoides, an annual species, and Hordeum bulbosum, a perennial species, were grown in containers in the open. They were subjected to a series of defoliation treatments that comprised three clipping frequencies and three clipping heights in a full...
Tipo: Peer-Reviewed Reports
Palavras-chave: Annual vs. perennial grasses; Biomass partitioning; Defoliation treatments; Grasslands; Grazing response; Hordeum bulbosum; Israel; Mediterranean; Reproductive effort; Triticum dicoccoides; Vegetative vs. reproductive structures.
Ano: 2001

Caractérisation génétique de l’effort reproducteur de l’huître creuse, Crassostrea gigas, dans le cadre des mortalités estivales de juvéniles : Approch QTL
Provedor de dados: 5
Autores: Flahauw, Emilie.
The Pacific oyster, Crassostrea gigas, is a major aquacultured species whose production represents an economic interest at worldwide, european and french levels. However, this species undergoes summer mortalities recorded from the beginning of the 20th century and, since 2008, this phenomenon increased and threatens mainly juvenile oysters. Aquaculture production of oysters suffers consequences of mass mortalities, that’s why this phenomenon has been studied for many years. In France, the bacterium Vibrio splendidus and the Ostreid virus Herpes Virus 1 (OsHV-1) are often associated with mass mortality outbreaks of juveniles oysters and it was demonstrated that selected individuals for resistance to summer mortality were able to slow the increasing in viral...
Tipo: Text
Palavras-chave: Huître creuse du Pacifique; Crassostrea gigas; Mortalités estivales; Survie; Effort reproducteur; Imagerie par Résonance Magnétique; Histologie; Marqueurs microsatellites; Marqueurs SNP; Cartographie de liaison; Détection de QTL; Pacific oyster; Crassostrea gigas; Summer mortality; Survival; Reproductive effort; Magnetif Resonance Imaging; Histology; Microsatellites; SNPs; Linkage mapping; QTL detection.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00233/34377/33786.pdf

Gametogenetic cycle and reproductive effort assessed by two methods in 3 age classes of Pacific oysters, Crassostrea gigas, reared in Normandy
Provedor de dados: 5
Autores: Royer, J; Seguineau, Catherine; Park, K; Pouvreau, Stephane; Choi, K; Costil, K.
Two methods were used to estimate the reproductive output of female Pacific oysters reared in Normandy: histology with image analysis and ELISA (Enzyme-Linked lmmunoSorbent Assay) which allowed the quantification of egg protein. Condition indices, gonad area and gametogenetic stages of the oysters were determined in the entire population (males and females) between May and October 2005. All investigations were performed in 3 age classes: oysters in their first, second or third years (corresponding to spat, half-grown and market-sized oysters, respectively). Both quantitative histology and ELISA provided similar results in terms of reproductive effort (illustrated by the gonado-somatic index, GSI) except during the GSI drop, corresponding to spawning, which...
Tipo: Text
Palavras-chave: Reproductive effort; Image analysis; Gametogenetic cycle; ELISA; Crassostrea gigas; Condition index.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4305.pdf

Mortalité et croissance de l'huître creuse C. gigas dans le bassin de Marennes Oléron. Résultats obtenus sur le site atelier de Ronce-Perquis en 1997-1999
Provedor de dados: 5
Autores: Soletchnik, Patrick; Le Moine, Olivier; Faury, Nicole; Razet, Daniel; Geairon, Philippe; Robert, Stephane; Goulletquer, Philippe; Taillade, Sylvie.
The 1999 monitoring of the C. gigas mortality rates showed a 32 to 40% loss for the on-bottom rearings located on the Ronce-Perquis oyster bank. In 1997, the averaged mortality rate varied between 23 and 29% without significant site effect. These mortality rates were ranging from 17 to 32% in 1998 with significant limited mortality rate on site 4 (17%). However, those rates were underestimated by 7 to 8%, based on our 1999 study, Actually, the spatial distribution for these rates on 2 experimental sites divided into 25 subunits demonstrated a large variability ranging from 17-37% and 22-56% for sites 1 and 2, respectively. In spite this large variability, the mortality rates results were larger on the muddy bottom site. In contrast to site 1, the oysters...
Tipo: Text
Palavras-chave: Bay of Marennes Oleron; Crassostrea gigas; Reproductive effort; Biochemical composition; Growth; Sampling strategy; Mortality rates; Bassin de Marennes Oléron; Crassostrea gigas; Effort de reproduction; Composition biochimique; Croissance; Méthodologie d'estimation; Taux de mortalité.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/rapport-1641.pdf

Application of a dynamic energy budget model to the Pacific oyster, Crassostrea gigas, reared under various environmental conditions
Provedor de dados: 5
Autores: Pouvreau, Stephane; Bourles, Yves; Lefebvre, Sebastien; Gangnery, Aline; Alunno-bruscia, Marianne.
The Dynamic Energy Budget (DEB) model (Kooijman, S.A.L.M., 1986. Energy budgets can explain body size relations. J. Theor. Biol. 121, 269¿282; Kooijman, S.A.L.M., 2000. Dynamic Energy and Mass Budgets in Biological Systems. Cambridge University Press, Cambridge, 424 pp.) has been adapted to describe the dynamics of growth and reproduction of the Pacific oyster (Crassostrea gigas) reared in different areas under conditions ranging from controlled to natural. The values of the model parameters were estimated from available physiological data and from published information. The sets of data used to validate the model came from three long-term growth experiments (&gt; 5 months) performed on Pacific oysters reared under different conditions of food and...
Tipo: Text
Palavras-chave: Reproductive effort; Reproduction; Growth; Ecophysiology; Dynamic energy budget; Crassostrea gigas.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1817.pdf

Responses of diploid and triploid Pacific oysters Crassostrea gigas to Vibrio infection in relation to their reproductive status
Provedor de dados: 5
Autores: De Decker, Sophie; Normand, Julien; Saulnier, Denis; Pernet, Fabrice; Castagnet, Sophie; Boudry, Pierre.
Several Vibrio species are known to be pathogenic to the Pacific oyster Crassostrea gigas. Survival varies according to pathogen exposure and high mortality events usually occur in summer during gametogenesis. In order to study the effects of gametogenetic status and ploidy (a factor known to affect reproduction allocation in oysters) on vibriosis survival, we conducted two successive experiments. Our results demonstrate that a common bath challenge with pathogenic Vibrio splendidus and Vibrio aestuarianus on a mixture of mature, spawning and non-mature oysters can lead to significant mortality. Previous bath challenges, which were done using only non-mature oysters, had not produced mortality. Immunohisto-chemical analyses showed the affinity of Vibrio...
Tipo: Text
Palavras-chave: Experimental vibriosis; Crassostrea gigas; Vibrio; Survival distribution function; Triploidy; Reproductive effort.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00030/14108/11368.pdf

Gametogenic cycle and reproductive effort of the tropical blacklip pearl oyster, Pinctada margaritifera (Bivalvia : Pteriidae), cultivated in Takapoto atoll (French Polynesia)
Provedor de dados: 5
Autores: Pouvreau, Stephane; Gangnery, Aline; Tiapari, Jerome; Lagarde, Franck; Garnier, Matthieu; Bodoy, Alain.
The gametogenic cycle and the reproductive effort of the blacklip pearl oyster, Pinctada margaritifera, cultivated in Takapoto lagoon were studied for a 1-year period (March 1997-April 1998) by bimonthly observations of gonadal sections, dry tissue weights and gonadal index in a population of pearl oyster composed of three age-groups. pearl oysters attained sexual maturity in the end of their first year (height approximate to 40 mm), implying that P. margaritifera is a late-maturing species in comparison with other Pteriidae. This species was also confirmed to be a marked protandrous successive hermaphrodite in culture, with 100 % of males at first maturity and 75 % in older pearl oyster (height &gt; 120 mm). The general pattern of gametogenic activity,...
Tipo: Text
Palavras-chave: French Polynesia; Reproductive effort; Reproductive cycle; Tropical aquaculture; Gametogenesis; Blacklip pearl oyster; Polynésie française; Effort de reproduction; Cycle de reproduction; Aquaculture tropicale; Gamétogenèse; Huître perlière.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-1391.pdf

Influence du temps d'immersion sur l'activité reproductrice et sur la croissance de la palourde japonaise Ruditapes philippinarum et l'huître japonaise Crassostrea gigas
Provedor de dados: 5
Autores: Goulletquer, Philippe; Lombas, Ines; Prou, Jean.
Pour étudier l'influence du temps d'immersion sur deux espèces cultivées, la palourde japonaise Ruditapes philippinarum et l'huître japonaise Crassostrea gigas, un suivi saisonnier de croissance est réalisé à 3 niveaux d'émersion (12%, 29% et 46%) sur l'estran du bassin de Marennes-Oléron. Des différences interspécifiques apparaissent : une prise de poids de coquille hivernale chez Crassostrea gigas, un arrêt étant observé en période automnale pour Ruditapes philippinarum. Par ailleurs l'émission des gamètes est plus précoce (août) et proportionnellement plus importante pour Crassostrea gigas que pour Ruditapes philippinarum (septembre). Les performances de croissance, la prise de poids ainsi que la distribution des populations des deux espèces sont...
Tipo: Text
Palavras-chave: Effort de reproduction; Temps d'immersion; Ruditapes philippinarum; Crassostrea gigas; Reproductive effort; Immersion time; Ruditapes phi Lippinarum; Crassostrea gigas.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/00112/22374/20054.pdf

Effect of phytoplankton and temperature on the reproduction of the Pacific oyster Crassostrea gigas: investigation through DEB theory
Provedor de dados: 5
Autores: Bernard, Ismael; De Kermoysan, Goulwen; Pouvreau, Stephane.
DEB theory can be used to obtain a detailed description of energy allocation in organisms and the control of this allocation by temperature and food concentration. In this study, we modified the model of Bourlès et al. (2009) developed for the Pacific oyster, Crassostrea gigas, to improve the description of reproductive effort. The model was amended in two ways: a new set of parameters was incorporated and a full description of gonad construction in spring was added, with a new state variable. The application of this model to a dataset for oyster growth measured in four bays over two years showed that this model better described reproductive effort, without modifying overall growth dynamics. We then explored the reproductive responses of oysters to their...
Tipo: Text
Palavras-chave: DEB model; Crassostrea gigas; Gametogenesis; Reproductive effort; Spawning date; Functional response.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00059/17047/14606.pdf

Effets de la turbidité sur les palourdes adultes Ruditapes philippinarum (Adams &amp; Reeve) : croissance, mortalité, effort de reproduction, composition biochimique
Provedor de dados: 5
Autores: Daou, Rafik; Goulletquer, Philippe.
Following observations on disparity in the growth of the Manila clam bred in the field, laboratory experiments were conducted to test the turbidity. This factor influenced the growth and mortality of Manila clam. The reproductive effort, growth and mortality of two populations were followed, one being cultivated in water with high levels on silt. A biochemical survey permitted the response to the effect of mineral particles to be estimated
Tipo: Text
Palavras-chave: Mortality; Reproductive effort; Biochemical changes; Ruditapes philippinarum; Turbidity; Mortalité; Effort de reproduction; Composition biochimique; Ruditapes philippinarum; Turbidité.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/publication-2876.pdf

Biochemical composition and energy value of Crassostrea gigas (Thunberg) cultured in the bay of Marennes-Oleron
Provedor de dados: 5
Autores: Deslous-paoli, Jean-marc; Heral, Maurice.
In the bay of Marennes-Oleron the dry flesh of Crassostrea gigas ranged from 29 to 52% proteins, 10 to 23% ash, 6 to 20% lipids and 0 to 4% carbohydrates of which 48.3 ± 21.6% were glycogen. The energy value ranged from 18.84 to 23.47 joule. Mg(-1) ash free dry weight (mean 20.27 J. mg(-1). Reproductive effort varied from 17.8 to 55.9% dry weight for males, and 43.1 to 61.9% for females during the first and third year of reproduction respectively. A high energy value for female gametes (23.47 to 26.24 J. mg(-1) dry tissue) was mainly due to a higher level of lipids (17.3 to 23% of dry tissue) in female gametes as compared to that in male gametes (5.9 to 12.3% of dry tissue). During the period of mass-loss which began in October and finished in March, the...
Tipo: Text
Palavras-chave: Crassostrea gigas; Winter loss of flesh; Reproductive effort; Energy value; Biochemical composition; Crassostrea gigas; Amaigrissement hivernal; Effort de reproduction; Valeur énergétique; Composition biochimique.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/publication-2872.pdf

Effets de la surcharge en seston minéral sur les palourdes Japonaises adultes Ruditapes philippinarum
Provedor de dados: 5
Autores: Daou, Rafik.
Negative effects of high turbidity, frequently seen at Marennes-Oleron bay in winter, on Manila clam Ruditapes philippinarum are experimentally studied with two samples during gametogenetic period may september 1987. Thes clams reared at high level of silt (178 mg/l) reduce their growth to about 32% the reproductive effort estimated by gameto-somatic weight index is reduced to 40 %. The high turbid ity is responsible of a twice mortality rate.
Tipo: Text
Palavras-chave: Turbidité; Ruditapes philippinarum; Composition biochimique; Effort de reproduction; Mortalité; Turbidity; Ruditapes philippinarum; Biochemical evolution; Reproductive effort; Mortality.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/00430/54175/55516.pdf

Effect of rosette size, clonality and spatial distribution on the reproduction of  Vriesea carinata (Bromeliaceae) in the Atlantic Forest of Paraná, southern Brazil
Provedor de dados: 39
Autores: Silva,Marcelo Aparecido de Souza; Varassin,Isabela Galarda.
ABSTRACT Plant size and clonality are important traits for explaining the reproductive effort of clonal plants. Larger plants can invest more resources into reproduction, and clonality is known to increase reproductive effort. Moreover, reproductive effort is influenced by environmental variation, and so the spatial distribution of plants may affect plant reproductive effort. We investigated the effect of plant size, clonality and spatial distribution on the reproductive effort of Vriesea carinata in the Atlantic Forest in the state of Paraná, Brazil. We marked twenty individual plants and measured their rosette size, biomass and number, as well as rosette reproductive effort (number of flowers, fruits and seeds). We also evaluated the relationship between...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Clonal growth; Morphological variation; Reproductive effort; RNSM; Vriesea.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062016000300401