Gametogenic cycle and size at first sexual maturity in female Chlamys (Azumapecten) farreri farreri (Jones & Preston, 1904) (Bivalvia: Pectinidae) in western Korea

The gametogenic cycle and number of spawning seasons per year of the female Chlamys (Azumapecten) farreri farreri were investigated by qualitative and quantitative analyses, and also the size at 50% of group sexual maturity (the size of first sexual maturity) was calculated to inform natural living resource management. In qualitative histologic analysis, the gametogenic cycle of this species can be classified into five successive stages: early active stage, late active stage, ripe stage, partially spawned stage, and spent/inactive stage. The spawning season occurs annually from July to September. In quantitative statistical analysis using an image analysis system, the patterns of monthly changes in reproductive cells were shown to be maximum in June and then dropped sharply from July to September. From these data, it is apparent that the C. (A.) farreri farreri has a unimodal annual gametogenic cycle. Shell heights at 50% of group sexual maturity were estimated as 51.47?mm and was 100% for scallops over 61.0?mm.