Pearl Culture

Seasonal and monthly changes in biochemical components and condition indices of the gonadal-visceral mass (GVM), gill, mantle, and adductor muscle of pearl oyster Pinctada radiata were analyzed from May 2012 to May 2013 in Eastern Egyptian Mediterranean coast in relation to reproductive cycle to provide information about the suitable time for implantation surgery. Protein was the major structural part of GVM and adductor muscle which was utilized to supply energy for late gonad development and spawning. Glycogen in adductor muscle might be for meeting the energy demands for spawning and gonad rebuilding, while accumulated gill glycogen was considered a major energy source for spawning and maintenance. Energy requirements were met by proteins and glycogen to a greater extent as compared to lipid. Year could be divided into three phases: somatic growth and maintenance, gametogenesis, and spawning phase. High condition index (CI) and fatness values were observed in May and June, whereas the lowest were observed after spawning (August). Contrarily, the shell component index minimum value was recorded in May then it increased till it reached the maximum value in August. The suitable time for pearl implantation surgery was October as oysters would be more energetic.

Since the late 1880s, Greeks have been involved in Australian pearling — initally in the pearl shell industry and then in pearl cultivation. The signficant strength of the Greek contribution to Australian pearling far outweighed the actual numbers involved. Key Greek indivduals, families and regional groups who are featured include: Mary Dakas (nee Paspalis), most probably Australia’s only Greek female pearl lugger operator; her brothers Michael and Nicholas, of whom the latter went on to establish the internationally renowned Paspaley Pearling Company; Denis George, whose research and experiments were pivotal to the development of pearl cultivation in Australia; Michael G. Kailis, who eatableshed Broome’s first successful pearl farm; the Hartos brothers, George, Jack and Nicholas, who were part of the attempt to revive Australian pearling after World War II; and the pioneering early Kastellorizan pearlers who were later followed in the 1950s by crews from another Dodecanese island, Kalymnos.

It was by accident that I read the American author Horace Beck’s book, Folklore and the Sea. It was this book that helped to get me acquainted with the western maritime folklore. I decided to collect everything related to the moral and social traditions, practices, fables, popular songs, and adages on Kuwait and the Gulf maritime folklore, and put them all in a book to be in the hands of those interested in the field.

During my research of the different phases of Kuwait’s maritime heritage, I obtained a score of anecdotes, stories, and narratives. I was happy to have had the chance to interview many baḥḥāra ‘sailors’, nuwākhdha ‘dhow captains’, galālīf ‘shipwrights’, and merchants inside Kuwait and beyond. Recorded in this publication, all of them provided me with folkloric treasures.

I am indebted to the sailors who shared their stories with me, and my appreciation and acknowledgements go to them which can be found on every page of this book. I am also indebted to everyone whom my memory failed to mention. To historian Saif Marzooq al-Shamlan and his relative Ali Saleh al-Roumi, a deep appreciation for presenting me with folkloric materials related to pearl diving and sea shanties.

Much folklore has been lost, falling into oblivion without being recorded.
This is a great loss indeed.

Yacoub Y. Al-Hijji

Where:  The University of Adelaide & Online
When: 1-3 Dec 2021: 5-7pm, 1 Dec; 2-7.30pm, 2 Dec; 10am-7pm, 3 Dec (ACDS: UTC/GMT +10:30)
Register at https://www.eventbrite.com/e/206978507287 

Water describes and sounds the South in resonant and manifold ways.  This symposium attends to the tones and contours of Southern Waters as they flow across the ‘unique world’ of the ‘blue southern hemisphere’, connecting and infusing the landmasses and islands of the South while circulating through the hydrosphere that distinguishes our planet. It considers the pressure that water – or its absence – places on creative form and on critical thought, and how water gives shape to understandings and performances of place in the world. Located in South Australia and focused particularly on the regions of Australasia and southern/eastern Africa, along with South/Asia, it is interested also in how water offers a medium for thinking between the global South and the geographic South and in what it means to inhabit the driest state of the driest continent on earth.

Featuring readings, performances and screenings of work by acclaimed and emerging writers, choreographers and musicians, the symposium brings creative practitioners and critical thinkers together in a series of conversation panels that reflect on the waters that flood into and infuse Australian literatures, as well as on writing the absence of water in arid states; thinking through wet and dry forms and theories, and across the Indian Ocean; writing rivers in southern lands; immersive and fluid choreographies; and the bejeweling undersea and inland seas of Australia and the ‘oceanic south’.

Growth and reproduction patterns of the winged pearl oyster, Pteria sterna, cultivated in tropical environments of Mexico: Implications for pearl farming Patrones de crecimiento y reproducción de la concha nácar, Pteria sterna, cultivada en un ambiente tropical de México: Implicaciones para el cultivo de perlas ABSTRACT. 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 g 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.

A 48 kDa acidic and putative calcium-binding glycoprotein was isolated from pearls of the freshwater mussel Hyriopsis cumingii. This protein was compared with a related 46 kDa polypeptide, obtained from the nacreous shell of the same species. Separation by two-dimensional gel electrophoresis revealed that the difference in molecular weight is due to the higher extent of glycosylation of the 48 kDa protein existing in pearls. Evidence is presented that the sugar moieties of the protein contribute to crystal growth, starting with the nucleation step. In in vitro precipitation experiments, the 48 kDa glycoprotein of pearls directed the formation of round-shaped vaterite crystals while the 46 kDa glycoprotein of shells promoted formation of small irregular calcite particles. Furthermore, both proteins, 48 kDa/46 kDa, comprised carbonic anhydrase activity that has been implicated in CaCO(3) formation. Thus, a function of the isolated glycoproteins in biomineralization is proposed together with the mechanism by which they can stabilize different calcium carbonate polymorphs.