Recent Trends in Freshwater Pearl Farming in India

*Shailesh Saurabh, Sweta Pradhan and Sonal Suman*

#### **Abstract**

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.

**Keywords:** cultured pearl, *Lamellidens marginalis*, CIFA, mussels, farming

#### **1. Introduction**

The "Queen of Gems," pearl, has a long history of cultural significance and great commercial demand, making it one of the most profitable aquaculture ventures in countries with extensive bivalve resources. Pearl harvesting was once restricted to wild aquatic resources, but with the innovation and standardisation of pearl producing processes, it has become a profitable aquaculture practice. The stimulation of a defence mechanism, where some kind of irritant prompts the bivalves to exude the glossy nacre, which coats the irritant by progressively evolving into layers to create the pearl, is the essential biology responsible for the production of pearly gems [1]. The pearl production process and cultured pearls are driven by this defence event, which is replicated in captivity. However, the ability to make the gem is not found in all molluscan bivalves; rather, only those species with a nacreous layer beneath their shell may make pearls [2].

Commercial pearl production is currently taking place in a number of nations throughout the world, including China, Japan, Australia, Indonesia, French Polynesia, Cook Islands, Philippines, India, Sri Lanka, Bangladesh, Myanmar, Thailand, Malaysia, and Mexico [3, 4]. China and Japan are the main producers of freshwater and marine pearls, respectively, whereas China is the world's biggest producer of pearls, including both marine and freshwater pearls, with 3540 tonnes produced, accounting for 98% of global pearl production [2]. According to the recent FAO (2020) data, freshwater pearl production is continuing to decline, both in terms of volume and value [5], as seen in **Figures 1** and **2**. It's difficult to answer the question of what can be causing the drop in freshwater pearl output year after year. However, a number of causes, including urbanisation, pollution, climate change, longer pearl production cycles, habitat degradation, sedimentation, a scarcity of qualified manpower, pesticide issues, and the lack of implantation kits, may be to blame for the fall in freshwater pearl output. It is imperative that actions be taken by fisheries departments, policymakers, planners, research organisations, financing

**Figure 1.**

*Global freshwater pearl production in terms of quantity (2009–2018; FAO 2020). X-axis: The annual year of pearl production; Y axis: Freshwater pearl production in tonnes.*

**Figure 2.**

*Total output value of freshwater pearl production (2009–2018; FAO 2020). X-axis: The annual year of pearl production; Y-axis: Value of pearl production.*

*Recent Trends in Freshwater Pearl Farming in India DOI: http://dx.doi.org/10.5772/intechopen.99281*

agencies, export agencies, and others to increase freshwater production output, which will aid in the long-term development of the pearl business. In the marine sector, the pearls from the oyster species *Pinctada maxima* followed by *Pinctada margaritifera* dominate the pearl industry [2].

ICAR-CIFA is instrumental in recognising the importance of freshwater pearl culture in India and creating standardised culture technologies for pearl production in freshwater systems. Collection of mussels, pre-operative care, preparation and implantation of nucleus, post-operative care, culture, and harvest are the six essential phases in the creation of cultured pearls. Of these processes, the precise implantation of nucleus is the most crucial. In comparison to other aquaculture species, pearl cultivation necessitates patience and skill.

### **2. What is a pearl?**

A pearl is a gemstone that is generated by living organisms and is the only one of its kind. Bivalves create pearls as a result of an immunological reaction caused by a foreign particle introduced into their body. The gem is made up of 82–86% of aragonite crystals of calcium carbonate and organic proteins, which form the pearl's matrix, where calcium crystallises [6, 7]. One of the most prevalent proteins identified in pearls is conchiolin. It resembles mother of pearl, the inner nacreous lustrous layer of the shell.

#### **3. Historical development of pearl farming**

The English word pearl is derived from the Latin word *pirula* which means pear. The name comes from the fact that pearls are frequently pear-shaped. Since the dawn of time, people have been fascinated by pearls. Pearls were given the term "mukta" in classical Sanskrit, which means "purity" or "escape," alluding to the spirit of the mollusc's desire to escape and solidify as a pearl. Back in the days, procurement of the pearls was done by collecting them from the wild. The creation of these structures in the oyster has long been a source of speculation among ancient philosophers and naturalists. The Rig Veda, the oldest of the Indian Vedas, mentions pearls. Pearl presents are mentioned in Chinese literature dating back to 2200 B.C. Pearls are mentioned in the Indian epics Ramayana and Mahabharata. In Hindu literature, the fabled origin of pearls is linked to Krishna, the eighth avatar of Vishnu, the most significant Hindu divinity. On Pandaia's wedding day, Krishna retrieved pearls from the depths of the sea to adorn her and Indian brides still wear pearls on their wedding days today [8]. According to another narrative, the pearl was a prize for Krishna's victory over the monster Pankagna, and he used it to ornament his bride. In ancient China, it was believed that pearls originated in the brain of the fabled dragon. They were regularly delivered as tributes to emperors by foreign princes and found sparkling in the centre of representations of Gods [8]. Throughout Hebrew literature, the Bible, and the Koran, pearls are mentioned in awe-inspiring terms. King Vijaya, who invaded Sri Lanka in the 6th century B.C., is reported to have lavished pearl offerings to his father-in-law, the Pandyan King of Madurai. Megasthenes, the Greek Ambassador at Chandragupta Maurya's court in the 3rd century B.C., and later travellers like Marco Polo (1260–1300 A.D.) and others have left illustrious records of India's and Sri Lanka's pearl fishery. The Persian Gulf, the Red Sea, and the Gulf of Mannar's pearl bank have all been recognised as producing Oriental pearls. For at least three thousand years, oyster pearl fishing has been documented in the Gulf of Mannar [9]. Pearls reached its zenith in the Roman Empire [10].

#### *Update on Malacology*

In the 12th century A.D., the Chinese found a feasible method for producing pearly Buddha images from the cockscomb pearl mussel, *Cristaria plicata*. There were attempts to make pearls by hand all over the world outside of China. In 1761, Carl von Linnaeus, a Swedish biologist, claimed to have developed a method for producing pearls artificially in freshwater mussels [10]. The Japanese solved the mystery by creating blister pearls from the pearl oyster in 1893 and free spherical pearls from the pearl oyster in 1907. Tokichi Nishikawa and TatsuheiMise brought this perliculture technology to Japan after it was created by British biologist William Saville-Kent in Australia. In 1916, Nishikawa acquired the patent and married Mikimoto's daughter. Later, in Japan, Kokichi Mikimoto, who is regarded as the pioneer of modern pearl cultivation techniques in the nineteenth century, began commercial pearl manufacturing [2], which paved a path towards the present day culture technologies. To distinguish the Japanese pearls from the "natural pearl" produced by wild oysters/mussels, the term "cultured pearl" was coined. Marine pearl farming began in India in the early 1970s, while freshwater pearl culture began in 1989. The marine pearl culture technique was introduced by the ICAR-Central Marine Fisheries Research Institute, whereas the freshwater pearl culture technology was developed by the ICAR-Central Institute of Freshwater Aquaculture. Farmers have expressed a strong desire to participate in the program offered by the ICAR research institute. From 2012 to 2020, more than 2000 entrepreneurs were trained on various elements of freshwater pearl farming through a total of 21 training programmes. A large number of stakeholders have adopted this technology at their backyard as a result of these. Furthermore, a user-friendly manual in various Indian languages has been created to meet the needs of various kinds of aspirants and to reach out to more farmers. Moreover, with the collaboration of ICAR-CIFA scientists, DD Kissan Delhi Doordharsan National Channel, New Delhi produced a documentary film on 'Moti Ke Kheti', which has been highly welcomed by many sections of the Indian population. Later on, DD Kissan released a documentary film on YouTube in order to make freshwater pearl technology accessible to a larger number of people throughout the world.

#### **4. Distribution of freshwater pearl mussels**

As per the studies conducted world-wide, the first appearance of pearl producing molluscs precedes to 530 million years [11] with 10,000 species of bivalve reported from across the planet [12]. China harbours more than 100 species of freshwater mussel out of which 10 species belonging to the Unionidae and Margaritiferidae family are being utilised for commercial production of pearls. Few of them include *Hyriopis cumingii, C. plicata, Lamprotula leai, Lamprotula rochechouarti* and *Margaritiana dahurica*. The freshwater pearl market of China is occupied by the pearls obtained from *H. cumingii* followed by *C. plicata* as they offer the ease of operation along with better quality pearls [2]. The freshwater pearl industry of Japan is dominated by *Hyriopis schlegelii* and *Margaritiana dahurica* [2]. The species *H. schlegelii* has strong ability to secrete nacre. Another freshwater mussel species native to North America, *Potamilus alatus*, has the ability to produce high quality black pearls [2]. Due to over-exploitation of European pearl mussel *Margaritifera margaritifera* in search of pearl the species now comes under endangered category and lots of projects are running to revive the natural population of this important species. The distribution of different freshwater pearl mussel is compiled and presented in **Table 1**.

India is a home to around 3270 molluscan species and 1100 out of them are bivalves [62] The marine bivalves count reaches up to 625 species, 88 of which are

#### *Recent Trends in Freshwater Pearl Farming in India DOI: http://dx.doi.org/10.5772/intechopen.99281*



#### **Table 1.**

*Distribution of freshwater pearl mussels in different countries.*

endemic [63]. As far as the freshwater mussel species are concerned, around 52 species have been reported from Indian waters including stagnant to slow flowing water bodies [64]. Nevertheless, large scale production of pearls is being carried with three species categorised under the Unionidae family i.e. *L. marginalis, L. corrianus* and *Parreysia corrugata* [30, 65].
