The identification of novel peptides or proteins that regulate growth, reproduction, adaptation and metabolism is essential for studying physiology in bivalves. However, in bivalves, most bioactive substances are expected to be unidentified. Therefore, we aimed to identify peptides or proteins that affect the physiology of bivalves. In this project, Search for genes encording of bioactive peptides or protein from the visceral ganglion of the pen shell (Atrina pectinata). Pen shell is an important bivalve in fisheries. The results obtained from this project will contribute to the development of efficient seedling production technology and to the elucidate the physiological mechanism common to all bivalves.