Recent Trends in Freshwater Pearl Farming in India

Cultured pearls have an important place in international trade. The Vedas, the Bible, and the Koran all mentioned pearls, and they are regarded as one of the highest honours. Pearls are generated in nature when an irritant, such as a sand grain or a parasite, is swept into the pearl molluscs and lodged within it, where it is coated with micro-layers of nacre, a lustrous substance made up of 80–90 per cent aragonite crystals of CaCO3. The ICAR-Central Institute of Freshwater Aquaculture (CIFA), Kausalyaganga, Bhubaneswar, India, has created a base technology for cultivating pearls in freshwater habitats, recognising the scope and value of freshwater pearl production. Indian pond mussel, Lamellidens marginalis is the major species used in freshwater pearl aquaculture. In addition, ICAR-CIFA has pioneered a novel feature of freshwater pearl farming. The Institute has also taken the lead in disseminating freshwater pearl culture technology to the country’s fish farming communities, entrepreneurs, researchers, and students to build a sustainable model for the country’s socio-economic development. In this chapter, we will briefly cover pearls and their types, their historical significance, the spread of pearl mussels of freshwater origin in various countries, pearl biomineralisation, pearl farming techniques, and factors affecting pearl quality, among other things.

Transcription of Genes Involved in Biomineralization in Two Mantle Morphs of Pearl Oyster, Pinctada Persica

A few species of mollusks display color variation in their soft tissues. In pearl oysters, the color polymorphism in mantle tissue is associated with the color and radiance of shell and pearl. The study of biomineralization related genes in mantle tissue of pearl oysters can be used as a suitable approach to better identify the molecular mechanisms that influence shell and pearl quality and color variations. In this study, we investigated the transcription of biomineralization-related genes in black and orange mantle morphotypes of pearl oyster, Pinctada persica in both warm and cool seasons using quantitative real-time PCR. Our results showed that the genes involved in biomineralization of the prismatic and nacre layer, i.e.; ASP, KRMP, MRNP34, SHELL, SHEM1B, LINKINE, PIF, SHEM5, NACREIN, and in pigmentation (TYR2A) were significantly highly expressed in orange phenotype compared to those of black one, suggesting the existence of different genetic processes between two color morphs of mantle tissue and the more active role of genes in orange morphotype. In black mantle phenotype, ASP, KRMP, SHEM5 and PIF and in the orange phenotype, only KRMP and PRISM showed difference in seasonal expression. This study provides an accurate understanding of the mantle trait of P. persica.

THE CONSUMER PERCEPTION ON QUALITY OF THE PEARL JEWELRY CRAFTS PRODUCTS MATARAM

The research aims to determine consumer perception on the quality of pearl jewelry products in Mataram. The population is consumers of pearl jewelry products, and the respondent determination technique is purposive sampling. The number of sample taken is 100 people. To answer the problem posed, the Ideal-Point Model is used. The model measures the gap (difference) between what is perceived and what consumers need. The result shows that the interest of consumers in purchasing pearl jewelry is mainly due to pearl quality, followed by other quality attributes. The quality value gap is quite large in the attributes of conformity to specifications, frame material, aesthetic value, price, and pearl jewelry design. Even though there is a value gap in some quality attributes, overall quality of Sekarbela pearl jewelry products is very good according to consumer perception.Keywords:Perception, Consumer, Quality, Crafts, Pearls

Whole transcriptome sequencing and biomineralization gene architecture associated with cultured pearl quality traits in the pearl oyster, Pinctada margaritifera

BackgroundCultured pearls are unique gems produced by living organisms, mainly molluscs of the Pinctada genus, through the biomineralization properties of pearl sac tissue. Improvement of P. margaritifera pearl quality is one of the biggest challenges that Polynesian research has faced to date. To achieve this goal, a better understanding of the complex mechanisms related to nacre and pearl formation is essential and can now be approached through the use of massive parallel sequencing technologies. The aim of this study was to use RNA-seq to compare whole transcriptome expression of pearl sacs that had producing pearls with high and low quality. For this purpose, a comprehensive reference transcriptome of P. margaritifera was built based on multi-tissue sampling (mantle, gonad, whole animal), including different living stages (juvenile, adults) and phenotypes (colour morphotypes, sex).ResultsStrikingly, few genes were found to be up-regulated for high quality pearls (n = 16) compared to the up-regulated genes in low quality pearls (n = 246). Biomineralization genes up-regulated in low quality pearls were specific to prismatic and prism-nacre layers. Alternative splicing was further identified in several key biomineralization genes based on a recent P. margaritifera draft genome.ConclusionThis study lifts the veil on the multi-level regulation of biomineralization genes associated with pearl quality determination.