Consulta: creatorFacets:"Lo, Cedrik"
Registros recuperados: 12
Data/hora: 13/06/2024 13:10:54

Determination of gender in the pearl oyster pinctada margaritifera
Provedor de dados: 5
Autores: Chavez-villalba, Jorge; Soyez, Claude; Huvet, Arnaud; Gueguen, Yannick; Lo, Cedrik; Le Moullac, Gilles.
The pearl industry in French Polynesia is based on exploitation of natural stocks of the black-lip pearl oyster (Pinctada margaritifera); it generates an annual turnover of 90 million euros. Improvements in pearl quality need genetic studies to improve the populations. This pearl oyster is a protandric species, where the sex-ratio normally is biased towards males. There is an increasing interest in gender control to find the mechanisms to augment female proportions for management purposes. This review summarizes information on exogenous and endogenous factors regulating gender in this and other bivalves and concludes that P. margaritifera is a protandric hermaphrodite, developing as a male during the first two years and without evidence of an effect from...
Tipo: Text
Palavras-chave: Pearl oyster; Pinctada; Hermaphrodite; Temperature; Food; Stress; Sex genes; Sex steroids.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00040/15100/12543.pdf

Yes, it turns: experimental evidence of pearl rotation during its formation
Provedor de dados: 5
Autores: Gueguen, Yannick; Czorlich, Yann; Mastail, Max; Le Tohic, Bruno; Defay, Didier; Lyonnard, Pierre; Marigliano, Damien; Gauthier, Jean-pierre; Bari, Hubert; Lo, Cedrik; Chabrier, Sebastien; Le Moullac, Gilles.
Cultured pearls are human creations formed by inserting a nucleus and a small piece of mantle tissue into a living shelled mollusc, usually a pearl oyster. Although many pearl observations intuitively suggest a possible rotation of the nucleated pearl inside the oyster, no experimental demonstration of such a movement has ever been done. This can be explained by the difficulty of observation of such a phenomenon in the tissues of a living animal. To investigate this question of pearl rotation, a magnetometer system was specifically engineered to register magnetic field variations with magnetic sensors from movements of a magnetic nucleus inserted in the pearl oyster. We demonstrated that a continuous movement of the nucleus inside the oyster starts after a...
Tipo: Text
Palavras-chave: Pearl oyster; Pearl rotation; Biomineralization.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00275/38598/37127.pdf

Growth Performance Comparison of Pinctada margaritifera Juveniles Produced by Thermal Shock or Gonad Scarification Spawning Procedures
Provedor de dados: 5
Autores: Ky, Chin-long; Lau, Christophe; Sham Koua, Manaarii; Lo, Cedrik.
The black-lipped pearl oyster Pinctada margaritifera is of high economic importance in French Polynesia. Arecent decline in pearl value led to the initiation of several genetic breeding programs aiming to improve production traits, including oyster shell growth, which dictates the time of grafting, size of the implanted nuclei, and biomineralization capacities. We assessed shell diameters on hatchery-produced spat to analyze juvenile growth performance of four half-sib families derived from polyandry (one dam crossed with two sires) and polygyny (two dams crossed with one sire) using gametes obtained by thermal shock or gonad scarification. Spat growth was monitored over 3 mo, with shell diameter measured weekly. Results revealed that the spawning method...
Tipo: Text
Palavras-chave: Pearl oysters; Pinctada margaritifera; Juvenile; Growth performance; Spawning procedure.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00310/42167/41470.pdf

The pearl oyster (Pinctada margaritifera) aquaculture in French Polynesia and the indirect impact of long-distance transfers and collection-culture site combinations on pearl quality traits
Provedor de dados: 5
Autores: Ky, Chin-long; Broustal, Floriane; Potin, Dan; Lo, Cedrik.
In French Polynesia, the P. margaritifera pearl aquaculture industry is spread over a vast area, as large as Europe. All the oysters for this the highly economically important activity are supplied from just a few collection lagoons, but they are grown in numerous sites across three archipelagos (Gambier, Society and Tuamotu). Many oyster transfers thus indirectly bring about grafting combinations mixing different geographic origins and production sites. This study aims to examine the impact of such graft combinations on cultured pearl quality traits. For this, six homogeneous and standardised experimental graft combinations (N = 6197) were conducted at commercial scale in the two growing locations the most frequently used in French Polynesia: Arutua atoll...
Tipo: Text
Palavras-chave: Pearl oyster; Pinctada margaritifera; Graft combinations; Pearl quality traits; Environment.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00477/58888/61444.pdf

Revisiting wild stocks of black lip oyster Pinctada margaritifera in the Tuamotu Archipelago: the case of Ahe and Takaroa atolls and implications for the cultured pearl industry
Provedor de dados: 5
Autores: Andrefouet, Serge; Thomas, Yoann; Dumas, Franck; Lo, Cedrik.
Spat collecting of the black lip oyster (Pinctada margaritifera) is the foundation of cultured black pearl production, the second source of income for French Polynesia. To understand spat collecting temporal and spatial variations, larval supply and its origin need to be characterized. To achieve this, it is necessary to account for the stock of oysters, its distribution and population characteristics (size distribution, sex-ratio). While the farmed stock in concessions can be easily characterized, the wild stock is elusive. Here, we investigate the distribution and population structure of the wild stock of Ahe and Takaroa atolls using fine-scale bathymetry and in situ census data. Stocks were surprisingly low (∼666,000 and ∼1,030,000 oysters for Ahe and...
Tipo: Text
Palavras-chave: Invertebrate population; Aquaculture; Spat collecting; French Polynesia; Atoll bathymetry; Wild stock assessment.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00343/45412/49287.pdf

Family effect on cultured pearl quality in black-lipped pearl oyster Pinctada margaritifera and insights for genetic improvement
Provedor de dados: 5
Autores: Ky, Chin-long; Blay, Carole; Sham-koua, Manaarii; Vanaa, Vincent; Lo, Cedrik; Cabral, Philippe.
Individual Pinctada margaritifera molluscs were collected from the Takapoto atoll (Tuamotu Archipelago, French Polynesia) and used to produce ten first generation full-sib families in a hatchery system, following artificial breeding protocols. After three years of culture, these progenies were transferred to Rangiroa atoll (Tuamotu Archipelago, French Polynesia) and tested for their potential as graft donors. A large-scale grafting experiment of 1500 grafts was conducted, in which a single professional grafter used ten individual donor oysters from each of the ten families, grafting 15 recipient oysters from each donor. The recipient oysters were all obtained from wild spat collection in Ahe (Tuamotu Archipelago, French Polynesia). After 18 months of...
Tipo: Text
Palavras-chave: Cultured pearl oyster; Pearl quality; Progeny effects; Heritability; Genetic selection; Pinctada margaritifera; French Polynesia.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00152/26310/24380.pdf

Integrated management of pearl culture in French Polynesia in the context of global change: Synopsis of existing results
Provedor de dados: 5
Autores: Gueguen, Yannick; Gaertner-mazouni, Nabila; Lo, Cedrik; Le Moullac, Gilles.
The paper presents a state of the art on knowledge of the black pearl oyster aquaculture at the scale of French Polynesia. It also introduces the main results obtained throughout the multi-partners POLYPERL project. The goal of this project was to develop an integrated and participative action-research of the pearl oyster culture system, focusing on the environmental, technological, economical and societal dimensions impacting the industry. The research proposed ranges from the understanding of biological phenomena of the production system to socio-economic aspects and governance of the industry, taking into account the management of anthropogenic, climate and health risks. We introduce here the different papers from the POLYPERL project that are compiled...
Tipo: Text
Palavras-chave: Pearl culture; Global change; French Polynesia; Pinctada margaritifera.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00346/45698/45320.pdf

A histological examination of grafting success in pearl oyster Pinctada margaritifera in French Polynesia
Provedor de dados: 5
Autores: Cochennec-laureau, Nathalie; Montagnani, Caroline; Saulnier, Denis; Fougerouse, Angelique; Levy, Peva; Lo, Cedrik.
Pearl oyster grafting is a complex surgical operation that should lead to pearl formation after approximately eighteen months. Although this technique has been used for many years in French Polynesia, the grafting process is still not standardised. While studies have been carried out in order to improve graft performance and yield, these remain highly variable due to post-grafting mortality, nucleus rejection and unreliable pearl quality, all of which constrain pearl farm profitability. The present study uses histological analysis to monitor oysters that either rejected or retained their nuclei. Both groups of oysters are compared in terms of evolution of the graft, which could influence retention, and the development of a pearl sac in cases where grafting...
Tipo: Text
Palavras-chave: Grafting process; Pearl formation; Pearl oyster; Pteriidae; Pinctada margaritifera.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00002/11288/7823.pdf

Effect of electrolysis treatment on the biomineralization capacities of pearl oyster Pinctada margaritifera juveniles
Provedor de dados: 5
Autores: Latchere, Oihana; Fievet, Julie; Lo, Cedrik; Schneider, Denis; Dieu, Stephanie; Cabral, Philippe; Belliard, Corinne; Ky, Chin-long; Gueguen, Yannick; Saulnier, Denis.
The present study investigated the effect of electrolysis on the biomineralization capacities of juveniles of the mollusk Pinctada margaritifera for the first time. Size-selected individuals from two groups, “Medium” and “Large”, from a multi-parental family produced in a hatchery system were subjected to electrolysis under a low voltage current over a nine-week experimental period. The growth of the juveniles was individually monitored and assessed weekly by wet weight and shell height measurements. At the end of the experiment, mantle tissue was sampled for biomineralization-related gene expression analysis. Electrolysis significantly increased pearl oyster growth in terms of shell height and wet weight for Large juveniles from the 5th and the 2nd week,...
Tipo: Text
Palavras-chave: Pearl oyster; Pinctada margaritifera; Electrolysis; Biomineralization; Gene expression.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00343/45410/44924.pdf

Age-dependence of cultured pearl grade and colour in the black-lipped pearl oyster Pinctada margaritifera
Provedor de dados: 5
Autores: Ky, Chin-long; Demmer, Jonathan; Blay, Carole; Lo, Cedrik.
Pinctada margaritifera is an economically important marine bivalve species for cultured pearl production in French Polynesian aquaculture. In order to evaluate the influence of donor oyster age on pearl quality traits, experiments were conducted over 6 years using both grafts and surgreffe operations. At harvest, 6 pearl quality traits were recorded and compared: surface defects, luster, grade, darkness level, and visual color. Analyzing the quality traits of pearls harvested in the initial graft process and those of pearls obtained from surgreffe experiments allowed a comparison of the influence of pearl sac cells originating from the initial mantle graft, which aged together with their recipient oysters. The results demonstrated a significant decrease...
Tipo: Text
Palavras-chave: Pearl oyster age; Pinctada margaritifera; Surgreffe; Pearl grade; Pearl colour.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00283/39472/37953.pdf

Macro-geographical differences influenced by family-based expression on cultured pearl grade, shape and colour in the black-lip "pearl oyster" Pinctada margaritifera: a preliminary bi-local case study in French Polynesia
Provedor de dados: 5
Autores: Ky, Chin-long; Blay, Carole; Aiho, Vaite; Cabral, Philippe; Le Moullac, Gilles; Lo, Cedrik.
In French Polynesia, the aquaculture of P. margaritifera is carried out in numerous grow-out sites, located over three archipelagos (Gambier, Society and Tuamotu). To evaluate the impact of macro-geographical effects of these growing sites on pearl quality traits, five hatcheries produced families were used as homogeneous donor oysters in an experimental graft. The molluscs were then reared in two commercial locations: Tahaa island (Society) and Rangiroa atoll (Tuamotu). At harvest, eight pearl quality traits were recorded and compared: surface defects, lustre, grade, circles, shape categories, darkness level, body and secondary colour and visual colour categories. Overall inter-site comparison revealed that: 1) all traits were affected by grow-out...
Tipo: Text
Palavras-chave: Pinctada margaritifera; Cultured pearl quality; Grow-out location; Environment.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00276/38687/37186.pdf

Mono- and polychromatic inner shell phenotype diversity in Pinctada margaritifera donor pearl oysters and its relation with cultured pearl colour
Provedor de dados: 5
Autores: Ky, Chin-long; Lo, Cedrik; Planes, Serge.
The pearl oyster Pinctada margaritifera has the specific ability to produce pearls with the widest range of colours among all pearl oyster species. This pearl colour diversity originates from the mantle biomineralising tissue (graft) of the donor oyster, which is originally responsible for the variety of colours of the inner shell surface. This study aimed to: 1) assess the geographic distribution and establish a first stocklist of the colourful oyster phenotypes used as donors in French Polynesia, and 2) investigate the phenotypic relation between inner shell colouration and the corresponding colour of harvested pearls. With the support of a pearl farmers' network, we investigated the different donor phenotype frequencies among five collection sites (Ahe,...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00354/46474/46249.pdf