Éditeur(s) : Elsevier
Résumé : 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 > 120 mm). The general pattern of gametogenic activity, fairly synchronous in both sexes, was comparable with that of other tropical bivalves: reproduction occurs continuously throughout the year with a maximal activity during the warm season (November-May). No resting period was observed. Quantitative growth data showed that P. margaritifera exhibits an annual synchronised polymodal spawning pattern, with two spawning peaks in age-group I (height approximate to 70 mm) and five in age-groups II (height approximate to 100 mm) and III (height approximate to 120 mm). Spawning was sometimes incomplete, nevertheless a clear relationship between gamete production (P-R, g) and size (height H, mm) was obtained: P-R = 5.26 x 10(-7) H-2.91 (R-2 = 0.99, p < 0.05). Estimation of P-R was used to calculate the annual reproductive effort in P. margaritifera. Reproductive effort (%) was similar to those calculated for temperate species and showed a progressive increase with the age of pearl oyster, from 7 % in age-group I to 38 % in age-group III. This study showed that, in a fairly stable tropical environment such as the Takapoto lagoon, P. margaritifera is a multiple spawner, which uses an opportunistic reproductive strategy, allowing investment all year around, of any surplus energy into gamete production. Surplus energy is ensured by the high pumping rates developed by this non-symbiotic bivalve to succeed in low seston conditions. (C) 2000 Ifremer/Cnrs/Inra/Ird/Cemagref/Editions scientifiques et medicales Elsevier SAS.
Le cycle et l'effort de reproduction de l'huître perlière à lèvres noires, Pinctada margaritifera, cultivée dans le lagon de Takapoto, ont été étudiés sur une période annuelle (de mars 1997 à avril 1998), par un suivi bimensuel des stades de maturation et des indices gonadiques, sur une population en élevage composée de trois groupes d'âge (1, 2 et 3 ans). Cette étude a confirmé que P. margaritifera est une espèce qui se reproduit tardivement par rapport aux autres Ptériidés (elle atteint sa maturité sexuelle à la fin de sa première année, pour une hauteur approximative de 40 mm). Par ailleurs, elle présente, en élevage, une protandrie marquée (100 % de mâles à première maturité, 75 % pour des huîtres âgées de trois ans). Le schéma général de sa gamétogenèse, relativement synchrone dans les deux sexes, est comparable à celui des autres bivalves tropicaux : la reproduction est quasiment continue (aucune période de repos sexuel) avec une activité accrue en saison chaude (de novembre à mai). L'analyse des variations du poids de la gonade suggère l'existence de deux pics d'émission de gamètes chez les huîtres de un an et cinq pics chez les huîtres de 2 et 3 ans (cycle de reproduction de type polymodal). Bien que ces émissions de gamètes soient parfois incomplètes, une relation entre la production de gamètes (PR, en g) et la taille de l'huître perlière (hauteur, H, en mm) a été établie : PR = 5,26 x 10-7 H2,91 (R2 = 0,99, p < 0,05). Ces résultats ont permis de calculer l'effort de reproduction de P. margaritifera à Takapoto et sur un bilan annuel : il augmente avec l'âge de l'huître perlière de 7 % pour le groupe d'âge I à 38% pour le groupe d'âge III. Ces valeurs annuelles sont similaires à celles calculées chez les bivalves de milieux tempérés. Cette étude a donc montré que, dans un environnement tropical assez stable tel que celui du lagon de Takapoto, P. margaritifera présente une reproduction continue, avec plusieurs pics d'émission de gamètes par an. Cette stratégie « opportuniste » permet l'investissement, de tout surplus d'énergie en production de gamètes, tout au long de l'année. Malgré la faible concentration du milieu en nourriture, ces surplus d'énergie sont assurés par les fortes capacités de filtration développées par cette espèce tropicale non-symbiotique.
Aquatic Living Resources (0990-7440) (Elsevier), 2000 , Vol. 13 , N. 1 , P. 37-48

Droits : 2000 Ifremer/Cnrs/Inra/Ird/Cemagref/Éditions scientifiques et médicales Elsevier SAS
http://archimer.ifremer.fr/doc/2000/publication-1391.pdf
DOI:10.1016/S0990-7440(00)00135-2
http://archimer.ifremer.fr/doc/00000/1391/

Éditeur(s) : Natl Shellfisheries Assoc
Résumé : 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 abiotic and biotic factors on gender during this phase. Later, pearl oysters progressively change to females, reaching a sex ratio close to 1:1 in specimens >8 years; at this stage, gender is apparently influenced by environmental parameters, but particularly by stress. Future research should seek to accurately determine the effect of temperature and food on sex ratios. Studies should be performed to characterize genes responsible for expression of gender. The use of hormones is a path that might be explored to influence the gender of pearl oysters.
Journal Of Shellfish Research (0730-8000) (Natl Shellfisheries Assoc), 2011-08 , Vol. 30 , N. 2 , P. 231-240

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00040/15100/12543.pdf
DOI:10.2983/035.030.0206
http://archimer.ifremer.fr/doc/00040/15100/

Éditeur(s) : Springer
Résumé : Pearl oysters belonging to the genus Pinctada (Bivalvia: Pteriidae) are widely distributed between the Indo-Pacific and western Atlantic. The existence of both widely distributed and more restricted species makes this group a suitable model to study diversification patterns and prevailing modes of speciation. Phylogenies of eight out of the 11 currently recognised Pinctada species using mitochondrial (cox1) and nuclear (18S rRNA) data yielded two monophyletic groups that correspond to shell size and presence/absence of hinge teeth. Character trace of these morphological characters onto the molecular phylogeny revealed a strong correlation. Pinctada margaritifera appears polyphyletic with specimens from Mauritius grouping in a different clade from others of the French Polynesia and Japan. Hence, P. margaritifera might represent a species complex, and specimens from Mauritius could represent a different species. Regarding the putative species complex Pinctada fucata/Pinctada martensii/Pinctada radiata/Pinctada imbricata, our molecular analyses question the taxonomic validity of the morphological characters used to discriminate P. fucata and P. martensii that exhibited the lowest genetic divergence and are most likely conspecific as they clustered together. P. radiata and P. imbricata were recovered as monophyletic. The absence of overlapping distributions between sister lineages and the observed isolation by distance suggests that allopatry is the prevailing speciation mode in Pinctada. Bayesian dating analysis indicated a Miocene origin for the genus, which is consistent with the fossil record. The northward movement of the Australian plate throughout the Miocene played an important role in the diversification process within Pinctada.
Marine Biotechnology (1436-2228) (Springer), 2011-04 , Vol. 13 , N. 2 , P. 181-192

Droits : Springer Science+Business Media, LLC 2010
http://archimer.ifremer.fr/doc/00035/14635/14015.pdf
DOI:10.1007/s10126-010-9278-y
http://archimer.ifremer.fr/doc/00035/14635/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The pearl oyster Pinctada margaritifera has the specific ability to produce pearls with the widest range of coloursamong 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 oysterphenotypes used as donors in French Polynesia, and 2) investigate the phenotypic relation between inner shellcolouration 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, Apataki, Takaroa,TakumeandMangareva). This donor evaluation was made during grafting of pearl oysters (N=49,938) obtainedfrom collector stations. Results showed that pearl production is mainly based on six common colourful donorphenotypes classified as monochromatic and polychromatic profiles, which shown different frequenciesamong the collection sites. Experimental grafts (N=4640)were then realised and subsequent culture conductedat a single site in order to avoid pearl colour variation due to environmental influences. Traceability between donors(N=232) and pearls (N=2776), revealed that: 1) yellow (gold) and aubergine (reddish) pearls could bemostly obtained by using the monochromatic yellowand red donor phenotypes, respectively, and 2) one third toone quarter of grey pearlswas inevitably harvested, whatever the polychromatic phenotype chosen as the donor,which leaves at least half the harvest composed of the attractive green and peacock colours. This preliminarystocklist of colour range together with analysis of the colour phenotype transmission between inner shell andpearl provide the basis for producing multiple pearl oyster “colour lines” through hatchery propagation andwould be helpful for future selective breeding programs.Statement of relevance: Donor shell colour selection predict colours of pearls
ISSN: 0044-8486

hal-01489153
https://hal-univ-perp.archives-ouvertes.fr/hal-01489153
DOI : 10.1016/j.aquaculture.2016.10.017

Éditeur(s) : Elsevier Science Bv
Résumé : In bivalve aquaculture, dominant fouling organisms are filter feeders which can compete for food with reared bivalves, sometimes causing mortality or reducing their growth rate. This study investigated the effect of biofouling on the farmed pearl oyster Pinctada margaritifera in two lagoons of French Polynesia. Survival, growth and reproduction of 2 year-old pearl oysters were monitored with regular sampling schedules, from the initial stage of colonization up to 20 months of biofouling accumulation. Control groups of pearl oysters were kept free of biofouling as is the current practice in pearl farms. After more than a year of monitoring, no significant difference was recorded in shell growth rate between pearl oysters reared with epibionts and the control group of pearl oysters, at both sites. Mean annual shell growth rate (height) was 30.5 ± 9.2 mm in Tahiti and 24.8 ± 7.7 mm in Mangareva. Neither the survival nor the reproduction indices were negatively affected by biofouling. In Mangareva, where biofouling development was quantified during 1 year, the rate of colonization appeared to be high during the first 3 months before slowing down. These results raise questions about the necessity of removing biofouling at this stage of pearl oyster production (i.e. before grafting).
Aquaculture (0044-8486) (Elsevier Science Bv), 2014-10 , Vol. 434 , P. 18-26

Droits : 2014 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00201/31188/29587.pdf
DOI:10.1016/j.aquaculture.2014.07.012
http://archimer.ifremer.fr/doc/00201/31188/

Éditeur(s) : HAL CCSD
Résumé : International audience
This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10 μg L− 1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM, CASP, MDR) were down-regulated. Based on the development of these molecular tools, we propose that the pearl oyster, P. margaritifera, could be used as a sentinel species for heavy metal contamination in the lagoons of tropical ecosystems.
. Marine Pollution Bulletin

hal-01526382
https://hal.archives-ouvertes.fr/hal-01526382
DOI : 10.1016/j.marpolbul.2017.03.012
PUBMED : 28320509

Éditeur(s) : Actes de colloques Ifremer, Tahiti, French Polynesia, 20 Feb - 4 Mar 1989, n°9, chap. 7, pp.57-66
Résumé : The first attempt to obtain artificial pearls from the black-lip pearl oyster Pinctada margaritifera in French Polynesia dates back to 1963. The pearl oyster culture has grown quickly especially since the eighties. This industry is now the first exportation in value of French Polynesia. 19 atolls of the Tuamotus island have at this time one or more farms and this activity has more and more attractiveness. The rise of this industry has consequently a lot of socio-ecomic repercussions on these atolls. However, as a young industry, the technics and the development are not always controlled and a lot of problems appeared these last years.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1989/acte-1494.pdf
http://archimer.ifremer.fr/doc/00000/1494/

Éditeur(s) : Public Library Science
Résumé : Studying the larval dispersal of bottom-dwelling species is necessary to understand their population dynamics and optimize their management. The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia's atoll lagoons. This aquaculture relies on spat collection, a process that can be optimized by understanding which factors influence larval dispersal. Here, we investigate the sensitivity of P. margaritifera larval dispersal kernel to both physical and biological factors in the lagoon of Ahe atoll. Specifically, using a validated 3D larval dispersal model, the variability of lagoon-scale connectivity is investigated against wind forcing, depth and location of larval release, destination location, vertical swimming behavior and pelagic larval duration (PLD) factors. The potential connectivity was spatially weighted according to both the natural and cultivated broodstock densities to provide a realistic view of connectivity. We found that the mean pattern of potential connectivity was driven by the southwest and northeast main barotropic circulation structures, with high retention levels in both. Destination locations, spawning sites and PLD were the main drivers of potential connectivity, explaining respectively 26%, 59% and 5% of the variance. Differences between potential and realistic connectivity showed the significant contribution of the pearl oyster broodstock location to its own dynamics. Realistic connectivity showed larger larval supply in the western destination locations, which are preferentially used by farmers for spat collection. In addition, larval supply in the same sectors was enhanced during summer wind conditions. These results provide new cues to understanding the dynamics of bottom-dwelling populations in atoll lagoons, and show how to take advantage of numerical models for pearl oyster management.
Plos One (1932-6203) (Public Library Science), 2014-04 , Vol. 9 , N. 4 , P. e95050

Droits : 2014 Thomas et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
http://archimer.ifremer.fr/doc/00197/30843/29210.pdf
DOI:10.1371/journal.pone.0095050
http://archimer.ifremer.fr/doc/00197/30843/

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background: Color polymorphism in the nacre of pteriomorphian bivalves is of great interest for the pearl culture industry. The nacreous layer of the Polynesian black-lipped pearl oyster Pinctada margaritifera exhibits a large array of color variation among individuals including reflections of blue, green, yellow and pink in all possible gradients. Although the heritability of nacre color variation patterns has been demonstrated by experimental crossing, little isknown about the genes involved in these patterns. In this study, we identify a set of genes differentially expressed among extreme color phenotypes of P. margaritifera using a suppressive and subtractive hybridization (SSH) method comparing black phenotypes with full and half albino individuals.Results: Out of the 358 and 346 expressed sequence tags (ESTs) obtained by conducting two SSH libraries respectively, the expression patterns of 37 genes were tested with a real-time quantitative PCR (RT-qPCR) approach by pooling five individuals of each phenotype. The expression of 11 genes was subsequently estimated for each individual in order to detect inter-individual variation. Our results suggest that the color of the nacre is partiallyunder the influence of genes involved in the biomineralization of the calcitic layer. A few genes involved in the formation of the aragonite tablets of the nacre layer and in the biosynthesis chain of melanin also showed differential expression patterns. Finally, high variability in gene expression levels were observed within the black phenotypes.Conclusions: Our results revealed that three main genetic processes were involved in color polymorphisms: the biomineralization of the nacreous and calcitic layers and the synthesis of pigments such as melanin, suggesting that color polymorphism takes place at different levels in the shell structure. The high variability of gene expression found within black phenotypes suggests that the present work should serve as a basis for future studies exploringmore thoroughly the expression patterns of candidate genes within black phenotypes with different dominant iridescent colors.
ISSN: 1471-2164

hal-01260141
https://hal.archives-ouvertes.fr/hal-01260141
https://hal.archives-ouvertes.fr/hal-01260141/document
https://hal.archives-ouvertes.fr/hal-01260141/file/Lemer-2015-BMCGenom-Identification.pdf
DOI : 10.1186/s12864-015-1776-x

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : Pearl culture industry represents one of the dominant business sector of French Polynesia. However, it still entirely relies on unpredictable spat collection success. Our aim was to assess the influence of natural plankton concentration fluctuations on maturation and spawning of the black lip pearl oyster Pinctada margaritifera, during a 4 months survey conducted in Ahe atoll lagoon. Plankton concentration was assessed by chlorophyll a extraction and by microscope counts while gonadic index, gonado-visceral dry weights and histology were used to measure pearl oysters reproduction activity. We found that (i) plankton concentration fluctuations were mainly related to wind regime, (ii) gametogenesis rate was mainly related to plankton concentration, (iii) spawning occurred when maximal gonad storage was reached. (iv) plankton concentration was the main spawning synchronizing factor. These results contribute explaining P. margaritifera spat collection variability in French Polynesian atoll lagoon. (C) 2012 Elsevier Ltd. All rights reserved.
Marine Pollution Bulletin (0025-326X) (Pergamon-elsevier Science Ltd), 2012 , Vol. 65 , N. 10-12 , P. 463-470

Droits : 2012 Elsevier Ltd. All rights reserved
http://archimer.ifremer.fr/doc/00101/21201/19697.pdf
DOI:10.1016/j.marpolbul.2012.03.027
http://archimer.ifremer.fr/doc/00101/21201/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Biofouling increases the operational and economic costs associated with pearl production. As currentprocedures for reducing oyster biofouling can be detrimental to survival and growth and may pollute thesurrounding environment developing alternative, biologically-mediated, methods could potentially in-crease both production and ecological sustainability. With this in mind, the present study investigatednatural cleaning of black-lipped pearl oysters, Pinctada margaritifera, by butterflyfishes (Chaetodon). Thefeeding behaviour of six butterflyfish species was examined at Rangiroa Atoll, French Polynesia: Chae-todon auriga, Chaetodon citrinellus, Chaetodon ephippium, Chaetodon lunulatus, Chaetodon trifascialis andChaetodon ulietensis. All species cleaned the surface of pearl oysters by removing epibionts (from 16% to40% of total biomass), although dietary variation may explain different cleaning efficiencies. Generalistomnivores (C. auriga, C. citrinellus, C. ephippium and C. ulietensis) were the most efficient cleaners (%cleaning range: 26e40% of total biomass). Within this group, C. ephippium removed the most biomass(average of 41%) targeting algae and anemones. However, C. auriga targeted the most diverse range ofepibionts, removing significant amounts of algae, sponges, tunicates, and anemones. These resultssuggest that foraging by butterflyfishes can substantially reduce biofouling on economically-importanttropical bivalves.
ISSN: 0272-7714

hal-01434152
https://hal-univ-perp.archives-ouvertes.fr/hal-01434152
DOI : 10.1016/j.ecss.2016.04.001

Résumé : Tahiti’s pearl farming industry plays a major socio-economic role in French Polynesia. In an increasingly competitive market where the production of high quality pearls becomes essential, research can help secure and ensure sustainable production. In that context, Ifremer, in close collaboration with the “direction des resources marines” (French Polynesian government agency) has developed research projects on the “sustainable development of pearl farming”. This program is organized along 3 axes: (1) understanding the animal physiology and initiating a genetically selective breeding program of donor oysters; (2) understanding pearl oyster larvae dispersal and recruitment; (3) understanding the molecular mechanisms underlying biomineralization processes during shell and pearl formation. It is in this frame that we have developed a highthroughput Expressed Sequence Tags pyrosequencing program on the calcifying mantle, combined with proteomic analyses of the shell and pearl. We analyzed 276738 EST sequences, leading to the constitution of a P. margaritifera mantle transcripts catalogue of 82 sequences potentially involved in biomineralization. Our results provided direct evidence that our ESTs data set covers a large number of the matrix proteins of P. margaritifera. In addition, our proteomic analysis enabled us to retrieve, in silico, all the sequences from P. margaritifera involved in the biomineralization process already published on databases. Integration of these two methods allowed, for the first time, the global composition of calcifying tissue and calcified structures to be examined in tandem.
Recent Advances in Pearl Research—Proceedings of the International Symposium on Pearl Research 2011.Edited by Shugo Watabe, Kaoru Maeyama and Hiromichi Nagasawa. 2013. ISBN : 978-4-88704-158-5. pp.184-194

Droits : 2013 TERRAPUB. All rights reserved.
http://archimer.ifremer.fr/doc/00167/27840/26049.pdf
http://archimer.ifremer.fr/doc/00167/27840/

Éditeur(s) : Edp Sciences S A
Résumé : This study was designed to measure responses of four-year-old black-lip pearl oysters (Pinctada margaritifera) to different temperatures and food concentrations and to identify the energy requirements of each sex. Oysters were fed a monospecific microalgal diet of Isochrysis affinis galbana (T-iso). Measurements of oxygen consumption and ingestion rates were carried out at 24 degrees C and 27 degrees C and at two algal (T-iso) concentrations: 5000 and 30 000 cell ml(-1). Glycogen content in adductor muscle, absorption efficiency and scope for growth were also estimated. Females and males responded differently to environmental factors, with food level being the most influential parameter. Oxygen consumption and absorption efficiency were significantly higher in females than in males, but males had significantly higher glycogen content than females. At high food concentration, glycogen content, ingestion rate, oxygen consumption, and scope for growth were significantly higher than at the low food concentration. Only absorption efficiency was significantly higher at the low food concentration. Oxygen consumption was significantly higher at 27 degrees C than at 24 degrees C. These results indicate that females and males have different bioenergetic functioning and that energy demands for reproduction are higher in females.
Aquatic Living Resources (0990-7440) (Edp Sciences S A), 2013-07 , Vol. 26 , N. 3 , P. 263-271

Droits : EDP Sciences, IFREMER, IRD 2013
http://archimer.ifremer.fr/doc/00157/26855/24980.pdf
DOI:10.1051/alr/2013059
http://archimer.ifremer.fr/doc/00157/26855/

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : In atoll lagoons of French Polynesia, growth and reproduction of pearl oysters are mainly driven by plankton concentration. However, the actual diet of black-lip pearl oysters P. margaritifera in these lagoons is poorly known. To fill this gap, we used the flow through chamber method to measure clearance rates of P. margaritifera in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia). We found : (i) that pearl oysters cleared plankton at a rate that was positively related to plankton biovolume, (ii) that nanoflagellates were the main source of carbon for the pearl oysters, (iii) that the quantity and origin of carbon filtrated by pearl oysters was highly dependent on the concentration and composition of plankton. These results provide essential elements for the comprehension of growth and reproduction variability of pearl oysters in atoll lagoons of French Polynesia.
Marine Pollution Bulletin (0025-326X) (Pergamon-elsevier Science Ltd), 2012 , Vol. 65 , N. 10-12 , P. 490-499

Droits : 2012 Elsevier Ltd. All rights reserved.
http://archimer.ifremer.fr/doc/00078/18888/16599.pdf
DOI:10.1016/j.marpolbul.2012.03.026
http://archimer.ifremer.fr/doc/00078/18888/

Éditeur(s) : FAO, Rome
Résumé : French Polynesia is currently the world's largest producer of cultured black pearls with exports worth U5$150 millions annually. The activity has become of prime socioeconomic importance the archipelagos with strong support and control of the government. In the mid-1980s, mass mortality of the black-lipped pearl oyster, Pinctada margarltlfera, has occurred in several atolls and challenged the development of pearl farming activity. Consequent studies and surveys have described several pathological conditions. None of those is considered to pose significant threat to the industry. However, they are monitored by a surveillance program in order to prevent and control emerging diseases. The government of French Polynesia has developed efforts to maintain high quality of the pearls and sustain demand of the markets. This paper reviews a successful model of development based on proactive policy and cooperation among stakeholders.
In : M. G. Bondad-Reantaso, S. E. McGladdery & F. C. Berthe. Pearl oyster health managment : a manual FAO Fisheries Technical Paper. N° 503, Rome, FAO : 120 p. (FAO, Rome), 2007 , Vol. 503 , P. 103-109

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2007/publication-3703.PDF
http://archimer.ifremer.fr/doc/00000/3703/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The pearl oyster Pinctada margaritifera has the specific ability to produce pearls with the widest range of coloursamong 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 oysterphenotypes used as donors in French Polynesia, and 2) investigate the phenotypic relation between inner shellcolouration 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, Apataki, Takaroa,TakumeandMangareva).Thisdonorevaluationwasmadeduringgraftingofpearloysters(N=49,938)obtainedfrom collector stations. Results showed that pearl production is mainly based on six common colourful donorphenotypes classified as monochromatic and polychromatic profiles, which shown different frequenciesamongthecollectionsites.Experimentalgrafts(N=4640)werethenrealisedandsubsequentcultureconductedat a single site in order to avoidpearl colour variation due to environmental influences. Traceability between do-nors (N = 232) and pearls (N = 2776), revealed that: 1) yellow (gold) and aubergine (reddish) pearls could bemostlyobtainedbyusingthemonochromaticyellowandreddonor phenotypes,respectively,and2)onethirdtoonequarterofgreypearlswasinevitablyharvested,whateverthepolychromaticphenotypechosenasthedonor,which leaves at least half the harvest composed of the attractive green and peacock colours. This preliminarystocklist of colour range together with analysis of the colour phenotype transmission between inner shell andpearl provide the basis for producing multiple pearl oyster “colour lines” through hatchery propagation andwould be helpful for future selective breeding programs.Statement of relevance: Donor shell colour selection predict colours of pearls
ISSN: 0044-8486

hal-01489247
https://hal-univ-perp.archives-ouvertes.fr/hal-01489247
DOI : 10.1016/j.aquaculture.2016.10.017

Éditeur(s) : 1st International Biennal Conference on Warm Water Aquaculture - Crustacea 02/9-11/83 Brigham Young University. Hawai
Résumé : Until recently, mollusc production in French Polynesia was only based upon fishing, for local consumption of edible bivalves mainly the oyster Saccostrea cucullata and for the exportation of pearl-oyster shells. As a consequence of parasitism problems on local oysters, a mollusc program was initiated by developping hatchery technics on introduced species of edible bivalves, Saccostrea echinata and Perna viridis, and cultivation methods in specialyy fitted up areas. Concerning pearl oyster Pinctada margaritifera the traditional shell production activity was recently reorganized to produce black culture pearls, inducing an increased demand of young implantable pearl-oysters. Hatchery spat production proved to be unsuccessful, and technics of collection and cultivation in lagoons were set up to supply the pearl oyster farming industry, and face the depletion natural stock. [NOT CONTROLLED OCR]

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1983/acte-4449.pdf
http://archimer.ifremer.fr/doc/00000/4449/

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : Bivalve larvae and hydrographic parameters were sampled over a range of spatio-temporal scales in a deep atoll lagoon. Bivalve larvae abundances were very high throughout the year: 18,550 m(-3) in average. Larvae were (i) concentrated at mid-depth with nocturnal ascent and diurnal descent, (ii) heterogeneously dispersed at the lagoon scale, (iii) subject to day-to-day variation in abundance and (iv) transferred between different parts of the lagoon providing evidence of intra-lagoonal connectivity. The primacy of physical factors was seen on large spatial scale with the diluting effect of water renewal and transfers by hydrodynamics. On smaller spatial scale, the primacy of biological processes was recognised, with larval swimming activity leading to dial vertical migration correlated with food concentration. Variations in larval abundance were driven by bivalve reproductive activity correlated with meteorological conditions (i.e. windy periods). Finally, relationship between bivalve larvae patterns and pearl oyster (Pinctada margaritifera) settlement structuring is discussed. (C) 2012 Elsevier Ltd. All rights reserved.
Marine Pollution Bulletin (0025-326X) (Pergamon-elsevier Science Ltd), 2012 , Vol. 65 , N. 10-12 , P. 453-462

Droits : 2012 Elsevier Ltd. All rights reserved.
http://archimer.ifremer.fr/doc/00101/21200/20690.pdf
DOI:10.1016/j.marpolbul.2011.12.028
http://archimer.ifremer.fr/doc/00101/21200/