Aichi Fisheries Cooperatives Use Smart Tech to Farm Triploid Oysters; Oysters Have Firmer Flesh, Richer Flavor

By Hiraku Harada / Yomiuri Shimbun Staff Writer

13:18 JST, March 14, 2026

TOYOHASHI — Members of fisheries cooperative associations have leveraged smart technologies to farm triploid oysters at Fukue Bay in Tahara, Aichi Prefecture.

The oyster sections of the Konakayama and Atsumi fisheries cooperative associations aim to turn the oyster into a local specialty product.

Triploid organisms possess three chromosomes, contrasting with diploids, which possess two. In triploids, chromosome segregation is dysfunctional during germ cell production, making it difficult for the organisms to produce sperm and eggs. Furthermore, the large number of chromosomes means an individual organism has the potential to become enormous.

Triploids are also used in agriculture, where their nature of producing few seeds is exploited to grow seedless watermelons and bananas.

Triploid oysters, meanwhile, are cultivated from seedlings produced in hatcheries. Owing to their nature, they lose few nutrients when spawning. As a result, they are resistant to shrinkage during summer and maintain a consistent quality throughout the year.

In the prefecture, efforts to cultivate the oysters are gaining steam in the city of Gamagori and other areas.

Bivalves have declined nationwide in recent years. In Tahara, a prolonged shortage has impacted heavily on clam fishing.

The two cooperative associations are focusing on triploid oysters as a new aquatic resource, aiming for stability and sustainability in the fishing industry. Since May last year, they have been making use of smart aquaculture, a process that utilizes information and communications technologies, to leverage data on the aquacultural environment and its operation.

The associations employ the “single-seed method,” whereby juvenile oysters are placed individually into cages. The method contrasts with the traditional method, which involves scallop shells being suspended from rafts. The single-seed method allows the oyster to grow unfixed, swaying with the waves. The process tightens their flesh, enhances their rich taste and results in a more beautiful shape.