Giant clams of the family Tridacnidae, classified into nine species in two genera, are found distributed in coral areas of the Indian and Pacific Oceans (Knop, 1996). Their meat is used for food, while the shells are used for ornamental purposes. Due to the great demand and the high prices, giant clam fishing has been on the rise, causing a rapid decline in the natural stock (Yamaguchi, 1977). Since the 1980's, giant clams have been listed in Appendix II of the Convention on International Trade in Endangered Species (CITES), and export of naturally caught giant clam products are restricted among the signatories of CITES.
Research on giant clam culture including seed production was initiated in Palau and Australia, and several techniques were developed in the 1980's. At present, many Pacific island countries work on giant clam culture, aimed at replenising the natural stocks and improving the supply of meat for local consumption and export. However, giant clam culture has not been fully successful as a business.
Of late there has been an increased demand for aquarium giant clams. A private company in the Marshall Islands cultures giant clams only for aquarium purposes and exports them. Palau and the Solomon Islands export a part of cultured giant clams as aquarium pets (Sant, 1995). Tonga began exporting cultured giant clams as pets to USA in 1995, but it has not been successful in exporting them to Japan (Fa'anunu et al., 1996).
A former survey of giant clams as food in Japan (Shang et al., 1991) also revealed that the market scale of aquarium giant clams was small. A very recent economic study on giant clam fisheries in Okinawa by Kuronuma and Tamashiro (1997) did not provide any information about aquarium giant clams.
The present survey was conducted to assess the feasibility of exporting giant clams cultured in the Pacific island countries to Japan as aquarium pets. It was carried out between 13 and 26 October 1997 in Tokyo and Osaka which are the main distribution bases in Japan, and in Okinawa which is a major giant clam supplying place in the country.