Press Release

July 3, 2012

Incorporated Administrative Agency, Fisheries Research Agency

Successful development of low-cost hanging culture techniques for pen shells

  • Techniques were developed for large-scale and low-cost culture of pen shell Atrina pectinata. It involved improving containers and introducing the rope raft method.
  • Fish farmers have tested the method and produced results of a mean survival ratio of 60% or over in 2 to 3 months of culture and a 2.1-fold increase of the mean weight of the adductor muscle.

Atrina pectinata is a large clam of Family Pinnidae, widely inhabiting sandy and muddy inner bay areas in Western Japan, and is an important fishery species. The catch has been large from old times particularly in the Ariake Sea, which was once a major production area. However, the resource has sharply dropped; and collection of pen shells by tool-equipped divers in Isahaya Bay, which was a major fishing area, has been suspended since 1993. This was mainly caused by changes in the environment of the seabed and frequent appearance of oxygen deficient water near the sea bottom. The Fisheries Research Agency has developed techniques for culturing pen shells suspended in the middle sea layer, where the shells can grow to commercial sizes even under the current environmental conditions of the Ariake Sea.

The Agency has focused on simple and low-cost methods, which are easy for fish farmers to introduce, improved the containers for the shells, introduced the rope raft method, and successfully developed economic and practical techniques for culturing pen shells in large scales at low costs. The rope raft method reduces the cost by 400 thousand yen annually compared to bamboo rafts. Suspended culture of pen shells has been already tested by fish farmers and has produced good results, such as a mean survival ratio of 60% or over in 2 to 3 months of culture and a 2.1-fold increase of the mean weight of the adductor muscle.


* This study was funded by the entrusted project of the prefecture government of Nagasaki, entitled “Development of pen shell suspended culture techniques,” which is one of the “Projects for developing technologies for promoting fisheries in the Ariake Sea” subsidized by the Fisheries Agency.


One-year-old pen shell used in the verification test (shell length: 14 cm)