Pearl culture is the most lucrative aquaculture industry in the Pacific Islands, and is an ideal development activity for remote, otherwise-impoverished atolls. Commercial farmers in the U.S.-affiliated Pacific Islands must be hatchery-based, offering opportunity for value-added improvements from triploidy for little additional cost. Techniques for inducing triploidy in Pinctada margaritifera will be developed by refining practices established for edible oysters and other Pinctada species. Cytochalasin B and 6- DMAP will be tested at different timings, exposures, and concentrations. Percentage triploids and survival of larvae and spat will be tracked. This research represents the first known triploidy trials with tropical bivalves and the first use of 6-DMAP in Pinctada. Advantages of triploidy may be more pronounced in tropical animals with extended reproductivity in even faster growth. The widespread use of triploid bivalves suggests a good likelihood of success in Phase I. Phase II efforts will subsequently quantify commercial advantages of triploid pearl oysters. Triploid animals will be seeded, and the success rates and value of pearls from triploid and diploid animals compared. Reduced age at first seeding, increased pearl size, perpetually sterile gonads and avoiding stresses of pre-operative conditioning could all potentially increase pearl production or values and improve farm profitability. ANTICIPATED RESULTS & POTENTIAL COMMERCIAL APPLICATIONS OF RESEARCH BPI could rapidly incorporate triploidy into our hatchery operations in Hawaii and Majuro, and hatchery projects in Cook Islands, Thailand and Phillippines. Farm revenues could increase for little additional cost. Increased profitability is particularly crucial to start-up farms in the fledgling hatchery-based industry in Hawaii and the Pacific. Few other development options are feasible for these rural areas. Pearl farming offers diverse employment opportunities, and socio-economic benefits including reversing rural-urban drift, and encouraging supportive industries. Pearls could boost exports and increase foreign exchange. American pearls might substitute for imports-primarily from Japan - currently worth over $400 million annually.