Current pearl grafting techniques were developed in the early 1900s and have changed little since... more Current pearl grafting techniques were developed in the early 1900s and have changed little since. They involve the sacrifice of donor pearl oysters to provide graft tissue (saibo) that is implanted into host oysters. This study assessed the feasibility of using regenerated graft tissue for pearl production in the 'black-lip' pearl oyster, Pinctada margaritifera. Twelve days after grafting with regenerated graft tissue, there was complete encapsulation of the nucleus by the fully developed pearl-sac and the first layer of organic matrix had been secreted. Sixteen days after grafting, the pearl-sac was completely integrated with host tissue. The epithelial cells in the pearl-sac continued to secrete the organic matrix layer but there were no signs of nacre deposition at this stage. However, after three months of culture, nuclei in oysters grafted with regenerated mantle tissue were completely covered with nacre. The average nacre thickness on pearls produced from regenerated (0.547 ± 0.01 mm, n = 8) and normal (0.532 ± 0.01 mm, n = 8) mantle tissue did not differ significantly (p > 0.05). Nacre secretion rates, over the 80 day period subsequent to pearl-sac formation were 6.84 ± 0.1 μm day(-1) and 6.66 ± 0.1 μm day(-1) for oysters grafted with regenerated and normal mantle tissue, respectively. These means were not significantly different (p = 0.258). Our results clearly show that regenerated mantle tissue can function successfully as saibo for pearl production in P. margaritifera. This finding could provide significant benefits to pearl farmers and a basis for further development of current pearl grafting practices.
The grafting process used for pearl production in pearl oysters triggers a significant haemocyte ... more The grafting process used for pearl production in pearl oysters triggers a significant haemocyte response which has an influence on the quality of pearls formed. One hundred and ten selected healthy adult Pinctada margaritifera were grafted for pearl production. Beginning two days after grafting, oysters were sacrificed regularly until the 48th day and the pearl-sacs of sampled oysters were sectioned for histological analysis. The level of haemocytes present in the pearl-sacs decreased overtime with the samples from day 2 showing the highest levels. Haemocyte levels also varied between samples from a particular day. The exact cause(s) of varying levels of haemocyte accumulation during pearl-sac development in P. margaritifera is not known. However, it is reasonable to assume that haemocyte production is positively related to the degree of damage caused to host oyster tissues during the grafting procedure. While haemocytes have an important wound healing role in pearl oysters, excess...
Anthropogenic emissions of carbon dioxide (CO 2 ) from fossil fuel combustion and deforestation a... more Anthropogenic emissions of carbon dioxide (CO 2 ) from fossil fuel combustion and deforestation are rapidly increasing the atmospheric concentration of CO 2 and reducing the pH of the oceans. This study shows that predicted near-future levels of ocean acidification have ...
5 In May 2008, SPC's Aquaculture Officer visited Tonga to provide assistance to two projects ... more 5 In May 2008, SPC's Aquaculture Officer visited Tonga to provide assistance to two projects aimed at stimulating the small-scale, half-pearl (mabe) industry in Tonga's Vava'u group. A pearl shell carving training workshop was organised by SPC in Vava'u and involved local craftsmen and women who wished to improve their pearl shell and mabe handi- crafts production. Tokerau Jim, a
Gamete cryopreservation techniques have been applied to several bivalve mollusc species. However,... more Gamete cryopreservation techniques have been applied to several bivalve mollusc species. However, research activity in this area has primarily focused on cryopreserving gametes from edible oysters (Ostreiidae). Few studies have examined the effect of cryoprotectants and freezing protocols in the preservation of spermatozoa from cultured pearl oysters (Pteriidae). Pearl oyster producers are increasingly looking towards the development of improved family lines and, as a consequence, the ability to cryopreserve gametes would bring about significant benefits to the cultured pearl industry. In response to this need, we evaluated the effect of three cryoprotectant additives (CPA) on motility of spermatozoa from the black-lip pearl oyster, Pinctada margaritifera. These additives have previously been used to cryopreserve gametes of other bivalve species. The following CPA mixtures were evaluated: (1) 0.45M trehalose and 0, 0.64, 1.02 and 1.53 M dimethyl sulfoxide (Me(2)SO); (2) 0.2M glucose and 2M Me(2)SO and (3) 1.31 M propylene glycol (PG). The effects of four different freezing protocols on motility of P. margaritifera spermatozoa were also evaluated (slow, medium, medium-rapid and rapid cooling). This study showed that total motility was best retained when spermatozoa were cryopreserved in 0.45 M trehalose and 0, 0.64, 1.02 or 1.53 M Me(2)SO and frozen using slow to medium-rapid cooling rates (2.1-5.2 degrees Cmin(-1)). Rapid freezing through direct plunging of spermatozoa into liquid nitrogen resulted in the lowest overall retention of motility regardless of the CPA additive; however, CPA mixture also influenced retention of motility, with 0.2M glucose in 2M Me(2)SO and 1.31 M PG retaining the lowest levels of motility for the CPAs evaluated.
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1998
The sterol metabolism of Pacific oyster (Crassostrea gigas) spat was investigated. 3H-squalene, 3... more The sterol metabolism of Pacific oyster (Crassostrea gigas) spat was investigated. 3H-squalene, 3H-desmosterol and 3H-fucosterol were mixed with oleic acid and separately encapsulated in gelatin-acacia microcapsules (GAM). Spat were fed one type of GAM for 7 days and were then unfed for 2 days. No labeled sterols were detected in spat fed GAM containing 3H-squalene, demonstrating the absence of de
ABSTRACT The winged pearl oyster, Pteria penguin, is cultured primarily to produce half-pearls (m... more ABSTRACT The winged pearl oyster, Pteria penguin, is cultured primarily to produce half-pearls (mabé). The mabé quality is influenced by culture techniques, but there is limited information in this field. P. penguin with mean (±SE) dorso-ventral height of 250 ± 6.5 mm were used to investigate the influence of culture period and nucleus position on mabé quality. Oysters were relaxed using 1-propylene phenoxetol, and five nuclei were glued at different positions to the inner surfaces of the oyster shells; three on the more concave left valve and two on the right valve. Nucleated oysters were then cultured for 10 months under commercial pearl farming conditions at Savusavu in Fiji. Nacre deposited at the base and top of the nuclei was measured monthly, from the 6th to the 10th months of culture and the different qualities of mabé produced at different positions were scrutinized. Nacre thicknesses at the base and top of the resulting mabé were significantly different at different months (P < 0.05) and the rate of nacre deposition was highest during the warmer months. The different positions of nuclei on the valve greatly affected the quality of mabé formed. After a 10-month culture period, around 1 mm of nacre covered the nuclei although the best quality mabé were obtained after 9 months.
... Author Contact Information , E-mail The Corresponding Author , Erika Martínez-Fernández andPa... more ... Author Contact Information , E-mail The Corresponding Author , Erika Martínez-Fernández andPaul C. Southgate. ... Of these, only 510% produce gem quality pearls; this small percentage, however, accounts ... Dix, 1972, Dix, 1973, Jabbour-Zahab et al., 1992 and Garcia-Gasca et ...
... Héctor Acosta-Salmón Corresponding Author Contact Information , E-mail The Corresponding Auth... more ... Héctor Acosta-Salmón Corresponding Author Contact Information , E-mail The Corresponding Author and Paul C. Southgate. ... in this study were hatchery propagated (Southgate and Beer, 1997) and maintained in suspended culture on a long-line (Gervis and Sims, 1992) at ...
... Crawford, CM, Nash, WJ and Lucas, JS, 1986. , Spawning induction and larval and juvenile rear... more ... Crawford, CM, Nash, WJ and Lucas, JS, 1986. , Spawning induction and larval and juvenile rearing of the giant clam Tridacna gigas. Aquaculture 58, pp. 281295 Abstract | PDF (1138 K) | View Record in Scopus | Cited By in Scopus (8). Fassler, R., 1995. ...
Recent years have seen major developments in the culture and availability of tropical microalgae ... more Recent years have seen major developments in the culture and availability of tropical microalgae as a food source for tropical bivalve species. The nutritional value of seven small (< 9 μm) tropical microalgae species: two diatoms (Chaetoceros muelleri and ...
Current pearl grafting techniques were developed in the early 1900s and have changed little since... more Current pearl grafting techniques were developed in the early 1900s and have changed little since. They involve the sacrifice of donor pearl oysters to provide graft tissue (saibo) that is implanted into host oysters. This study assessed the feasibility of using regenerated graft tissue for pearl production in the 'black-lip' pearl oyster, Pinctada margaritifera. Twelve days after grafting with regenerated graft tissue, there was complete encapsulation of the nucleus by the fully developed pearl-sac and the first layer of organic matrix had been secreted. Sixteen days after grafting, the pearl-sac was completely integrated with host tissue. The epithelial cells in the pearl-sac continued to secrete the organic matrix layer but there were no signs of nacre deposition at this stage. However, after three months of culture, nuclei in oysters grafted with regenerated mantle tissue were completely covered with nacre. The average nacre thickness on pearls produced from regenerated (0.547 ± 0.01 mm, n = 8) and normal (0.532 ± 0.01 mm, n = 8) mantle tissue did not differ significantly (p > 0.05). Nacre secretion rates, over the 80 day period subsequent to pearl-sac formation were 6.84 ± 0.1 μm day(-1) and 6.66 ± 0.1 μm day(-1) for oysters grafted with regenerated and normal mantle tissue, respectively. These means were not significantly different (p = 0.258). Our results clearly show that regenerated mantle tissue can function successfully as saibo for pearl production in P. margaritifera. This finding could provide significant benefits to pearl farmers and a basis for further development of current pearl grafting practices.
The grafting process used for pearl production in pearl oysters triggers a significant haemocyte ... more The grafting process used for pearl production in pearl oysters triggers a significant haemocyte response which has an influence on the quality of pearls formed. One hundred and ten selected healthy adult Pinctada margaritifera were grafted for pearl production. Beginning two days after grafting, oysters were sacrificed regularly until the 48th day and the pearl-sacs of sampled oysters were sectioned for histological analysis. The level of haemocytes present in the pearl-sacs decreased overtime with the samples from day 2 showing the highest levels. Haemocyte levels also varied between samples from a particular day. The exact cause(s) of varying levels of haemocyte accumulation during pearl-sac development in P. margaritifera is not known. However, it is reasonable to assume that haemocyte production is positively related to the degree of damage caused to host oyster tissues during the grafting procedure. While haemocytes have an important wound healing role in pearl oysters, excess...
Anthropogenic emissions of carbon dioxide (CO 2 ) from fossil fuel combustion and deforestation a... more Anthropogenic emissions of carbon dioxide (CO 2 ) from fossil fuel combustion and deforestation are rapidly increasing the atmospheric concentration of CO 2 and reducing the pH of the oceans. This study shows that predicted near-future levels of ocean acidification have ...
5 In May 2008, SPC's Aquaculture Officer visited Tonga to provide assistance to two projects ... more 5 In May 2008, SPC's Aquaculture Officer visited Tonga to provide assistance to two projects aimed at stimulating the small-scale, half-pearl (mabe) industry in Tonga's Vava'u group. A pearl shell carving training workshop was organised by SPC in Vava'u and involved local craftsmen and women who wished to improve their pearl shell and mabe handi- crafts production. Tokerau Jim, a
Gamete cryopreservation techniques have been applied to several bivalve mollusc species. However,... more Gamete cryopreservation techniques have been applied to several bivalve mollusc species. However, research activity in this area has primarily focused on cryopreserving gametes from edible oysters (Ostreiidae). Few studies have examined the effect of cryoprotectants and freezing protocols in the preservation of spermatozoa from cultured pearl oysters (Pteriidae). Pearl oyster producers are increasingly looking towards the development of improved family lines and, as a consequence, the ability to cryopreserve gametes would bring about significant benefits to the cultured pearl industry. In response to this need, we evaluated the effect of three cryoprotectant additives (CPA) on motility of spermatozoa from the black-lip pearl oyster, Pinctada margaritifera. These additives have previously been used to cryopreserve gametes of other bivalve species. The following CPA mixtures were evaluated: (1) 0.45M trehalose and 0, 0.64, 1.02 and 1.53 M dimethyl sulfoxide (Me(2)SO); (2) 0.2M glucose and 2M Me(2)SO and (3) 1.31 M propylene glycol (PG). The effects of four different freezing protocols on motility of P. margaritifera spermatozoa were also evaluated (slow, medium, medium-rapid and rapid cooling). This study showed that total motility was best retained when spermatozoa were cryopreserved in 0.45 M trehalose and 0, 0.64, 1.02 or 1.53 M Me(2)SO and frozen using slow to medium-rapid cooling rates (2.1-5.2 degrees Cmin(-1)). Rapid freezing through direct plunging of spermatozoa into liquid nitrogen resulted in the lowest overall retention of motility regardless of the CPA additive; however, CPA mixture also influenced retention of motility, with 0.2M glucose in 2M Me(2)SO and 1.31 M PG retaining the lowest levels of motility for the CPAs evaluated.
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1998
The sterol metabolism of Pacific oyster (Crassostrea gigas) spat was investigated. 3H-squalene, 3... more The sterol metabolism of Pacific oyster (Crassostrea gigas) spat was investigated. 3H-squalene, 3H-desmosterol and 3H-fucosterol were mixed with oleic acid and separately encapsulated in gelatin-acacia microcapsules (GAM). Spat were fed one type of GAM for 7 days and were then unfed for 2 days. No labeled sterols were detected in spat fed GAM containing 3H-squalene, demonstrating the absence of de
ABSTRACT The winged pearl oyster, Pteria penguin, is cultured primarily to produce half-pearls (m... more ABSTRACT The winged pearl oyster, Pteria penguin, is cultured primarily to produce half-pearls (mabé). The mabé quality is influenced by culture techniques, but there is limited information in this field. P. penguin with mean (±SE) dorso-ventral height of 250 ± 6.5 mm were used to investigate the influence of culture period and nucleus position on mabé quality. Oysters were relaxed using 1-propylene phenoxetol, and five nuclei were glued at different positions to the inner surfaces of the oyster shells; three on the more concave left valve and two on the right valve. Nucleated oysters were then cultured for 10 months under commercial pearl farming conditions at Savusavu in Fiji. Nacre deposited at the base and top of the nuclei was measured monthly, from the 6th to the 10th months of culture and the different qualities of mabé produced at different positions were scrutinized. Nacre thicknesses at the base and top of the resulting mabé were significantly different at different months (P < 0.05) and the rate of nacre deposition was highest during the warmer months. The different positions of nuclei on the valve greatly affected the quality of mabé formed. After a 10-month culture period, around 1 mm of nacre covered the nuclei although the best quality mabé were obtained after 9 months.
... Author Contact Information , E-mail The Corresponding Author , Erika Martínez-Fernández andPa... more ... Author Contact Information , E-mail The Corresponding Author , Erika Martínez-Fernández andPaul C. Southgate. ... Of these, only 510% produce gem quality pearls; this small percentage, however, accounts ... Dix, 1972, Dix, 1973, Jabbour-Zahab et al., 1992 and Garcia-Gasca et ...
... Héctor Acosta-Salmón Corresponding Author Contact Information , E-mail The Corresponding Auth... more ... Héctor Acosta-Salmón Corresponding Author Contact Information , E-mail The Corresponding Author and Paul C. Southgate. ... in this study were hatchery propagated (Southgate and Beer, 1997) and maintained in suspended culture on a long-line (Gervis and Sims, 1992) at ...
... Crawford, CM, Nash, WJ and Lucas, JS, 1986. , Spawning induction and larval and juvenile rear... more ... Crawford, CM, Nash, WJ and Lucas, JS, 1986. , Spawning induction and larval and juvenile rearing of the giant clam Tridacna gigas. Aquaculture 58, pp. 281295 Abstract | PDF (1138 K) | View Record in Scopus | Cited By in Scopus (8). Fassler, R., 1995. ...
Recent years have seen major developments in the culture and availability of tropical microalgae ... more Recent years have seen major developments in the culture and availability of tropical microalgae as a food source for tropical bivalve species. The nutritional value of seven small (< 9 μm) tropical microalgae species: two diatoms (Chaetoceros muelleri and ...
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