Pearl Cultivation Research Articles

An update on freshwater pearl cultivation research and development in Nepal

An update on freshwater pearl cultivation research and development in Nepal

A novel birnavirus identified as the causative agent of summer atrophy of pearl oyster (Pinctada fucata (Gould)).

The Akoya pearl oyster (Pinctada fucata (Gould)) is the most important species for pearl cultivation in Japan. Mass mortality of 0-year-old juvenile oysters and anomalies in adults, known as summer atrophy, have been observed in major pearl farming areas during the season when seawater temperatures exceed about 20 °C since 2019. In this study, we identified a novel birnavirus as the pathogen of summer atrophy and named it Pinctada birnavirus (PiBV). PiBV was first presumed to be the causative agent when it was detected specifically and frequently in the infected oysters in a comparative metatranscriptomics of experimentally infected and healthy pearl oysters. Subsequently, the symptoms of summer atrophy were reproduced by infection tests using purified PiBV. Infection of juvenile oysters with PiBV resulted in an increase in the PiBV genome followed by the atrophy of soft body and subsequent mortality. Immunostaining with a mouse antiserum against a recombinant PiBV protein showed that the virus antigen was localized mainly in the epithelial cells on the outer surface of the mantle. Although the phylogenetic analysis using maximum likelihood method placed PiBV at the root of the genus Entomobirnavirus, the identity of the bi-segmented, genomic RNA to that of known birnaviruses at the full-length amino acid level was low, suggesting that PiBV forms a new genus. The discovery of PiBV will be the basis for research to control this emerging disease.

Faktor-Faktor Budidaya Kerang Mutiara di Desa Maijuring Kecamatan Aru Tengah Kabupaten Kepulauan Aru

Pearl cultivation began to develop, especially in Maluku Province. With the increasing cultivation of pearl mussels, the demand for pearl seeds is also increasing, but this is also hampered by a lack of supply of seeds from wild catches or obstacles during seed production, namely high mortality at the spawning stage and in general the growth and survival of shellfish species is greatly influenced. by important factors, namely temperature and food availability and other important factors, on this basis the author conducted research which aims to determine the factors of pearl oyster cultivation in Maijuring Village, Aru Tengah District, Aru Islands Regency. The type of research used is Qualitative Descriptive analysis. With sea water samples and 5 pearl oyster cultivators. The sampling technique used is purposive sampling which uses the criteria of people who cultivate pearl oysters. The data collection techniques used are observation, documentation and interviews. The data analysis technique used is SWOT analysis. The results of the research show that in Maijuring Village there are several factors in cultivating pearl oysters, namely water quality, feed availability, water temperature, water depth, water salinity, water pH, population density, cultivation land maintenance such as water quality which is influenced by temperature, namely 26.9, pH namely 7.76, and salinity 34.42, and depth 20-30m. from the surface.

The Puzzle of the Thinly Coated Pearl

This article takes animal materials as contested elements of ecological knowledge production. The focus is on Ago Bay, a Japanese inlet at the mid-twentieth-century global epicenter of demand for “cultured” pearls that formed inside surgically manipulated shellfish. In 1950s Ago, long-established pearl cultivators complained that their pearls had thinner outer coatings than they expected. Tracing shifting ideas about shellfish stocking densities, smallholder aquaculture, rates of pearl formation, and the accumulation of organic wastes in water over time, this article reconsiders the puzzle of the thinly coated pearl. In its guise as host to thousands of working pearl farms and a network of researchers studying the effects of intensive pearl cultivation, Ago Bay is a rich site from which to think about aquaculture’s ecological and infrastructural limits. The bay was not simply a natural receptacle that housed pearl cultivation. The shore, water, seafloor, and floating pearl oyster raft-and-cage systems could be—and were—defined as infrastructure that could undergo regulation and rearrangement. Pearl cultivation did not just happen in the bay; it was part of the bay—and it reshaped ideas about the bay. This paper is part of a special issue entitled “Making Animal Materials in Time,” edited by Laurence Douny and Lisa Onaga.

Green Entrepreneurship Based On Local Characteristics and Culture To Support Sustainable Eco-Tourism: A Case Study

The research problem is that West Nusa Tenggara lacks the local characteristics to support sustainable eco-tourism and culture. The case study of the quantitative descriptive method was used to describe the motivation behind the establishment of sustainable eco-tourism, the evaluation of triple helix support factors (government, academia, and green product business actors) in the development of the ecotourism, evaluation of internal factors of ecotourism, SWOT analysis, and the establishment of a green entrepreneur development strategy model in weaving and pearl industries. The results of the study show that the pearl shell breeding industry in West Lombok, which consists of pearl shellfish culture, treatment, pearl shell growing, pearl cultivation, pearl processing, pearl processing into jewelry, processing pearl shell waste into jewelry, and souvenirs, as well as the use of pearl shell meat for consumption, has high economic value and provides strong appeal for tourists. Pearl shell businesses from upstream to downstream can be used as a typical green tourism model of West Nusa Tenggara with high educational value. The woven fabric industry with natural dyes from various types of leaves, skins, and logs in Pringgasela village can empower 1,250,000 women.

Cloning and functional analysis of a trypsin-like serine protease from Pinctada fucata martensii

Trypsin-like serine proteases (TLSs) play various roles in dietary protein digestion, hemolymph coagulation, antimicrobial peptide synthesis, and, in particular, the rapid immune pathways activated in response to pathogen detection. The cultured pearl industry, of which Pinctada fucata martensii is one of the most important species, is plagued by disease, thus leading to large economic losses. Herein, the molecular mechanisms underlying the innate immune response of P.f. martensii were explored. First, immune effector molecules from the P.f. martensii genome were screened and a TLS-like gene encoding a protein with a trypsin domain, herein designated as PmTLS, was identified. A multi-sequence alignment indicated a low sequence homology between PmTLS and other mollusk TLS-like proteins. Furthermore, a neighbor-joining phylogenetic analysis indicated that PmTLS has the closest genetic relationship to a Crassostrea gigas TLS. Additionally, real-time quantitative PCR (qPCR) analysis showed that PmTLS mRNA is constitutively expressed in all of the 6 examined P.f. martensii tissues, with significantly higher expression noted in hemocytes relative to the other tissues examined (p < 0.05). P.f. martensii samples were then challenged with various pathogen-associated molecular patterns (PAMPs), including lipopolysaccharide, peptidoglycan, and polyinosinic acid. In the challenge groups, PmTLS was significantly upregulated in hemocytes at 48 h post-challenge when compared to the unchallenged controls. Furthermore, treatment with recombinant PmTLS (rPmTLS) also significantly inhibited the growth of most of the examined gram-negative bacteria tested in vitro (p < 0.05), but it had little effect on the growth of the examined gram-positive bacteria. When examining morphological changes via transmission electron microscopy, rPmTLS treated bacteria exhibited morphological changes such as plasma wall separation. Thus, rPmTLS appears to play a bactericidal role by destroying bacterial cell membranes or cell walls, which subsequently leads to a release of the cellular contents and cell death. The findings presented herein have enabled further characterization of the immune defense mechanisms in P.f. martensii and may lead to improved disease control methods for the pearl cultivation industry.

Spatio-Temporal Variation of the Abundance of Pearl Oyster (Pinctada mazatlanica) Spat and Its Relevance in the Location of Suitable Sites for Extensive Pearl Oyster Culture

In general, pearl cultivation has advanced with organisms produced and improved in hatchery; however, wild spat collection is still the primary source for commercial cultivation. In Mexico, progress toward pearl oyster hatchery spat production is yet in the experimental stage. The only three farms established in the country (Guaymas, La Paz, and Cozumel Island) rely on extensive culture. Constant spat supply is imperative to ensure a successful operation; at La Paz Bay, however, larval uptake of the pearl oyster Pinctada mazatlanica in artificial collectors has always been low. This study aimed to assess spatio-temporal and bathymetric patterns of spat distribution across the area to locate suitable sites to install spat collecting stations. Our results showed significant differences (P < 0.05) between stations. Mogote, Caimancito, Punta Colorada, and Gaviota Island were the stations with the highest spat abundance at 1-m depth in July–September after 40 and 60 days of immersion. The data were also analyzed with generalized linear models. The best models, selected with the Akaike and Bayesian criteria, suggest that 1-m depth, 40- and 60-day immersion time, and site (particularly, Caimancito Beach, Punta Colorada, and Gaviota Island) contributed significantly to explaining the highest catches (mean: 5–8 organisms/collector) of P. mazatlanica spat in La Paz Bay. Therefore, the area within these sites should be considered suitable for installing the network of artificial collectors during the season of high spat abundance.

Antibacterial Effects of Drug-Coated Pearl Nuclei Used for Freshwater Pearl Cultivation

In the cultivation of freshwater nucleated pearls, the treatment technology of nucleated pearls is very important for the quality and yield of pearls. Pearl nuclei treated with astragalus extract, flavomycin, and oxytetracycline were found to possess anti-inflammatory and antibacterial effects depending on drug concentrations. To optimize the concentration of various drugs for the preparation of medicinal pearl nuclei to enhance pearl production Staphylococcus aureus and Aeromonas hydrophila were used as experimental strains. A comprehensive antibacterial circle diameter was taken as an indicator of drug efficacy. The response surface method based on a central composite design (CCD) was used to explain the combined effect of drugs and optimize their concentrations. The optimal concentrations of flavomycin, oxytetracycline, and astragalus extract were 9.10, 10.50, and 1.50 g/mL, respectively. In these conditions, the predicted antibacterial circle diameter was 1.83 cm and the measured value was 1.81 cm, accounting for a 0.5% relative error. The pearl nuclei coated with the abovementioned drug combinations had a strong antibacterial effect on both A. hydrophila and S. aureus, thus establishing a basis for the development and application of medicinal pearl nuclei.

Vertical Distribution of Dissolved Oxygen Concentration at The Sea Pearl Cultivation Development Site, West Lombok, Nusa Tenggara Barat

Titrimetric method or Winkler Methode was applied to determine dissolved oxygen (DO) in sea waters of The Sea Pearl Cultivation Developement Site, West Lombok during southeast monsoon of June 2021. The samples were taken in three (3) different location (Gili Gede, Gili Genting and Autorei) of the cultivation site at Sekotong waters, West Lombok, Nusa Tenggara Barat. Measurement results of physical parameters at those locations were characterized with salinity was ranging at 31.9 - 32.3 PSU, temperature was ranging at 28.4 – 29.7 0 C. The concentration of dissolved oxygen measured by titration method is ranging from 3.4 - 5.2 mg / L. High oxygen content is found in the water column with a depth of 25 m or below the layer of the aquatic column where sea shell pearls are developed or cultivated. This condition indicates that the presence of cultivated sea shell pearls has utilized dissolved oxygen in the process of respiration and oxidation of organic matter. Dissolved oxygen becomes an important abiotic factor for ecosystems that support the sustainability of marine life and marine aquaculture development efforts.

ANALISIS KESESUAIAN DAN DAYA DUKUNG LOKASI BUDIDAYA KERANG MUTIARA MABÈ (Pteria penguin) DI PERAIRAN PALABUSA KOTA BAU-BAU

Southeast Sulawesi region, especially the Palabusa waters area of Buton Regency, has become a center for cultivation of several economical species, one of which is the mabè pearl (Pteria penguin). This research was conducted with the aim of identifying the suitable area for the development of mabè pearl cultivation and determining the carrying capacity of the area in Palabusa waters in developing mabè pearl cultivation. This research was conducted in September to November 2020. The data collection was carried out in two parts, namely field and laboratory activities. The data obtained then were analyzed descriptively. The results of this study indicate that: (1) Physical, chemical and biological parameters in Palabusa waters indicate the potential site suitability for the development of mabè pearl cultivation are in the very suitable category (SS) is 128, 3 Ha, quite suitable (S) is 64,5 Ha and not suitable (N) is 47,7 Ha for mabè pearl cultivation; (2) The carrying capacity of Palabusa waters for the development of pearl mabè pearl culture is 847 units. Further research needs to be carried out, especially regarding social and economic aspects as well as other water quality parameters that affect the determination of the suitability of mabè pearl cultivation areas such as environmental pollution, waves and tides.

Integrated mRNA and miRNA expression profile analysis of female and male gonads in Hyriopsis cumingii

Hyriopsis cumingii is an important species for freshwater pearl cultivation in China. In terms of pearl production, males have larger pearls and better glossiness than females, but there are few reports focusing on the sex of H. cumingii. In this study, six mRNA and six microRNA (miRNA) libraries were prepared from ovaries and testes. Additionally, 28,502 differentially expressed genes (DEGs) and 32 differentially expressed miRNAs (DEMs) were identified. Compared with testis, 14,360 mRNAs and 20 miRNAs were up-regulated in ovary, 14,142 mRNAs and 12 miRNAs were down-regulated. In DEGs, the known genes related to sex determinism and/or differentiation were also identified, such as DMRT1, SOX9, SF1 for males, FOXL2 for females, and other potentially significant candidate genes. Three sex-related pathways have also been identified, which are Wnt, Notch, and TGF-beta. In 32 DEMs, the three miRNAs (miR-9-5p, miR-92, miR-184) were paid more attention, they predicted 28 target genes, which may also be candidates for sex-related miRNAs and genes. Differential miRNAs target genes analysis reveals the pathway associated with oocyte meiosis and spermatogenesis. Overall, the findings of the study provide significant insights to enhance our understanding of sex differentiation and/or sex determination mechanisms for H. cumingii.

Judging the Perle Japonaise: The Techno-Legal Separation of Culture from Nature in 1920s Paris.

This article traces the making of a techno-legal apparatus to regulate a new object: the "cultured" pearl. In the early 1920s, round pearls cultivated on Japanese farms provoked alarm within the Paris association whose members traded more pearls than anywhere in Europe. Despite their claims to be connoisseurs of surfaces, anti-cultivation pearl dealers in Paris asserted that a pearl's identity could only be ascertained by examining its inner structure. By mid-decade, dedicated pearl testing laboratories appeared and supported French court rulings about what to call the products of Japanese pearl cultivation in relation to "natural" pearls. The meanings of nature and culture were not fixed, but transformed in the 1920s, amid legal and technical efforts to know la perle japonaise inside out.

Implementasi Undang-Undang Nomor 24 Tahun 2011 Tentang Badan Penyelenggaraan Jaminan Sosial pada PT. Horiko Abadi Kabupaten Buleleng

Social security provides protection for workers in the socio-economic risks that befall workers in carrying out their work in the form of work accidents, illness, old age, or death. This thesis discusses the implementation of Law Number 24 of 2011 concerning the Social Security Administration at PT. Horiko Abadi, Buleleng Regency. Based on the description above, this study aims to determine the application of Law Number 24 of 2011 concerning the Social Security Administration at PT. Horiko Abadi, Buleleng Regency 2 legal sanctions against the company in the event of a violation of the provisions of the social security program. The research method used is the empirical juridical method. The location of this research was conducted at PT. Horiko Abadi, Buleleng Regency, a company engaged in the breeding of shellfish and pearl cultivation. Based on the research results, PT. Horiko Abadi has implemented social security protection for all permanent employees in the company in accordance with the provisions of Law Number 24 of 2011 concerning Social Security Administering Bodies, and sanctions for companies that have not implemented the provisions of Law Number 24 of 2011 Regarding the Social Security Administering Body, it is still in the guidance or warning stage until the company concerned can carry out the provisions of the legislation.

Case study on freshwater pearl cultivation at tribal district Chhindwara, Madhya Pradesh, India

Case study on freshwater pearl cultivation at tribal district Chhindwara, Madhya Pradesh, India

OPPORTUNITIES AND CHALLENGES FOR TOURISM DEVELOPMENT IN THE NUSA TENGGARA TIMUR REGION (NTT)

Besides the tourism sector can increase economic growth, it also does not damage the environment and even stimulates environmental conservation. The tourism sector has become a global trend in the past three decades. World Travel and Tourism Council (WTTC) in 1998. Problems: 1) What is the urgency of tourism in the NTT region? And 2) How do you deal with the challenges of developing tourism in the NTT region? This research is empirical legal research. The urgency of tourism in the NTT region, among others: paying attention to tourism in the province of East Nusa Tenggara (NTT), which has the character of an archipelago, most of which consists of marine waters and is still lagging behind, it seems that the urgency of tourism in NTT is dominated by sea tourism or nature, such as national parks, Marine Conservation Areas, and Nature Parks (TWA). This is evident through the existence of 8 (eight) marine waters conservation areas owned by NTT Province. In addition, NTT Province also has a lot of potential in the marine sector, such as marine resources for capture and aquaculture; the potential for seaweed cultivation; potential of salt resources; and the potential for pearl cultivation, all of the marine potential is very supportive and influences the urgency of tourism for the East Nusa Tenggara (NTT) Province. Efforts that can be made in order to deal with these challenges include: first, make improvements in the infrastructure sector, for example there is good coordination between the central and regional governments and cities in the NTT Province with regard to policies on water conservation area management or marine tourism in East Nusa Tenggara (NTT); second, maximizing the tourism potential in NTT through professional human resource de-velopment, improved tourism management facilities and third, online tourism publications optimized so that tourists are interested in traveling to the NTT Province; and in addition, supervise/control the applicable laws and regulations in ALKI that cross the sea waters, so that the existence of the ALKI does not interfere with the conservation of waters in the Sawu Sea.

Sex-changing patterns of Akoya pearl oyster (Pinctada fucata)

BackgroundPearl production by transplantation in Akoya pearl oyster (Pinctada fucata) is a biotechnology developed in Japan that skillfully utilizes the pearl-forming ability of oysters. In this method, cultured pearls are formed from a pearl nucleus and a small piece of mantle transplanted into the gonads of recipient pearl oysters. In this study, we hypothesized that the sex of the recipient pearl oyster might affect the quality of pearl produced. While some previous studies have examined the sex of Akoya pearl oyster, detailed information is lacking.ResultsTo investigate sex in Akoya pearl oyster, we collected small gonadal fragments from 1-year-old pearl oysters by biopsy. Using the collected gonad fragment, the sex of the oysters was determined by microscopic observation, and the remaining samples were stored for gene expression analyses. All oysters were labeled to distinguish each individual for serial samplings every four months over the 2-year study period. At the start of experiment, nearly all of the pearl oysters were male, but the male:female ratio ofmale decreased over the course of the experiment. Interestingly, the number of males increased after spring, during the breeding season. This suggests that, in pearl oyster, sex is affected by season. Expression analysis of sex-related genes (Dmrt2, Vtg, Zp) indicated that all genes were expressed in all individuals and all periods.ConclusionsThese results suggest that Akoya pearl oysters are hermaphroditic, and that females appear as necessary, such as during the breeding season. These findings could contribute to higher efficiency and quality of pearl cultivation.

Pcr-rflp para identificação de ostras perlí­­feras (Pinctada imbricate) do Brasil e Venezuela

As ostras do género Pinctada são de grande importí­¢ncia econômica devido ao seu uso extensivo na alimentação humana e cultivo de pérolas. Inclui quatro espécies: Pinctada radiata (Europa), P. imbricata (Atlí­¢ntico Ocidental) e P. fucata-martensi (Pací­­fico), sendo esta última uma espécie complexa, de difí­­cil diferenciação morfológica. Embora este complexo de espécies tenha vários estudos moleculares corroborando cada espécie como válida, ainda há dúvidas sobre a validade de P. imbricata no Sul do Atlí­¢ntico Ocidental. Neste trabalho realizou-se um estudo de RFLP com populações do Ceará, Rio de Janeiro, São Paulo e costa da Venezuela. Foram analisados genes mitocondriais (16S) e nucleares (IGS parcial). Este estudo confirma que os espécimes brasileiros e venezuelanos são geneticamente mais próximos í­Â s populações de P. imbricata do Caribe do que o complexo P. martensi-fucata. Esse resultado é importante para os produtores de ostras perlí­­feras, demonstrando que os estoques brasileiro e venezuelano não são compostos de espécies exóticas ou hí­­bridas de espécies indo-pací­­ficas.

Imidazole‐dicarboxylic Acid Nickel Complex as a Novel Grafting Agent for Pearl Oyster, Pinctada martensii

AbstractIn the pearl cultivation industry, the implantation of the nucleus is a critical step in the production process. The surgical insertion of the nucleus and the mantle results in a wound and stress that affect not only the survival chances of the pearl oysters but also the quality of the pearls produced. This study proposes a synthesized imidazole‐dicarboxylic acid nickel complex that may hold potential in assisting the wound healing and nacre formation processes. The acute toxicity of the complex to pearl oysters, Pinctada martensii, was examined in a dose–response study over a 90‐h exposure. The safe concentrations of the nickel complex determined using probit analysis were 0.916 mg/L and 0.471 mg/L for 72‐h and 96‐h treatments, respectively. The reliability of the regression was verified using the chi‐square test. The alkaline phosphatase (ALP) activity in different regions of the treated and control oysters, along with relevant blood biochemical indices, were measured over a 90‐d period to predict the potential effects of the nickel complex on wound healing and nacre formation. A significant increase in ALP activity in the mantle, together with elevated blood levels of Mg (II) and globulin, and reduced blood levels of Zn (II) and blood urea nitrogen were observed. These results indicate that the prepared nickel complex may hold promise in helping wound healing post mantle implantation, promote the secretion of nacre, and enhance the immunity of the oysters, thus ultimately improving the yield and quality of the pearls.

Making Space for Red Tide: Discolored Water and the Early Twentieth Century Bayscape of Japanese Pearl Cultivation.

"Red tide" has become a familiar shorthand for unusual changes in the color of ocean waters. It is intimately related both to blooms of creatures like dinoflagellates and to the devastating effects they pose to coastal fisheries. This essay tracks the early twentieth century emergence of discolored water as an aquacultural problem, known in Japan as akashio, and its trans-oceanic transformation into the terms and practices of "red tide" in the post-World War II United States. For Japan's "Pearl King" Mikimoto Kōkichi and his contacts in diverse marine scientific communities, the years-long cycle of guarding and cultivating a pearl oyster went together with the ascription of moral qualities to tiny creatures that posed a threat to farmed bayscapes of pearl monoculture. As akashio, discolored water went from curiosity to marine livestock pest, one that at times left dead pearl oysters in its wake. Red tide arose from the sustained study of the mechanisms by which changes in the biological and chemical composition of seawater might become deadly to exclusively-claimed shellfish along Japanese coastlines, but came to be seen as a way to understand aquatic manifestations of harm in other parts of the littoral world.

Growth and reproduction patterns of the winged pearl oyster, Pteria sterna, cultivated in tropical environments of Mexico: Implications for pearl farming

The winged pearl oyster, Pteria sterna, sustains a growing pearl industry in northwestern Mexico, where a subtropical climate prevails. In tropical areas of Mexico, pearl cultivation may be profitable, but insufficient information on the biology and ecology of the species limits the definition of protocols for creating pearl farms. We measured absolute growth, growth rate, reproductive stages, changes in oocyte size, and size at first maturity of juvenile P. sterna cultivated in Bahía de Acapulco over one annual cycle (2009–2010), and compared their response in this tropical area with reports from subtropical areas of Mexico. We also compared the von Bertalanffy growth model with one proposed in this study for aquaculture purposes. The growth rate was higher during the first six months (5.3 mm month–1) and then decreased to 3 mm month–1 until juveniles reached a size of 60 mm in one year. Growth rates were higher in February and lower in July through September. Both models described well the growth of P. sterna, but the adjustment and the estimation of parameters was better with the proposed model. Gametogenesis started in December 2009 at 50.9 mm (males) and 59.5 mm (females); gonad development occurred continuously throughout the year with a peak in February–March (~25–26 ºC; 2.8 µg L–1 chlorophyll a concentration), when the gonad index was highest and oocytes were larger. When compared to other studies conducted in subtropical areas, the species uses different strategies to channel available energy into growth and reproduction in tropical regions; P. sterna grows quickly in Bahía de Acapulco and may obtain the size necessary for grafting (70–80 mm shell height) in 15–17 months.