Growing Bigger Pearls

Biopacific Development Inc. (BPI) of San Francisco says it has created oyster and pearl growth enhancers (PGEs) that make pearl oysters grow faster and produce nacre more quickly. PGEs are biologically active substances that work by stimulating the metabolism of mantle tissue cells. BPI’s growth-enhancing products increase nacre deposition around a bead nucleus by up to 36% in only six months. BPI’s new product has been in development for more than two years. During the company’s experiments, using PGEs increased the size of black pearls and black-lipped pearl oysters (Pinctada margaritifera) by approximately .64 mm in six months. The growth of treated oyster shell increased by up to 22% over control oysters. Survival rates and nucleus retention rates remained unchanged, as did quality characteristics such as luster, shape, surface, and color.

Consider a typical margaritifera or maxima pearl, approximately 10-11 mm in diameter. To obtain pearls of this size, typically a nucleus of 6.5 mm or larger is implanted. Based on demonstrated results from BPI, where the average increase in total nacre deposition was .73 mm in six months, Biopacific’s technology will increase total nacre deposition by 1.5 mm in one year. That growth rate will transform the typical 10.5-mm pearl into a 12-mm pearl. Such an increase in size can nearly triple the value of that pearl, according to BPI, resulting in significantly higher farm profits. In addition, the second and third implants can be performed sooner because the production cycle is shorter-which means more profits, sooner.

PGEs may also benefit Japanese pearl growers. Given the now-shortened life span of many Japanese akoya pearl oysters, PGEs can help produce a shell of a given size in a shorter time. For akoya farmers, PGEs may be the only reliable way to harvest crops of pearls 8 mm and larger, says BPI.

While BPI’s testing was done primarily on South Seas pearl oysters, the benefits of PGEs are equally significant for akoya as well as Chinese and Japanese freshwater pearls. Initial tests used syringe injections of PGEs while the oysters were out of the water for washing and cleaning. A newer time-release capsule in six- or twelve-month versions is now being tested for insertion during the nucleation process.

For more information, contact Fred Ward at P.O. Box 341419, Bethesda, MD 20827; (301) 983-1990, fax (301) 365-0712, e-mail: