First report on the annual reproductive cycle of Atrina pectinata at Ulleung Island on the east coast of Korea

Abstract

The annual reproductive cycle of pen shell Atrina pectinata from Ulleung Island was investigated from November 2013 to October 2014 using histology. Gametogenesis commenced in January and when the surface water temperature was 12.6°C and pen shells showed early development phase with small oogonia from January to April, although fem females exhibited ripe eggs in their follicular epithelium. In April, the oocyte diameter increased rapidly, and fully mature eggs appeared in May. First spawning males and females were observed in June as the surface water temperature reached 19.3°C and July (23.2°C) respectively. The spawning activity continued until the end of September. Histology indicated that spawning peak of the females in Ulleung Island was July to August. During October to January, most of the pen shells were in spent and resting stages. Our data suggested that A. pectinata is a summer spawner, and their annual gametogenesis is closely associated with the seasonal variation in the surface water temperature. Resting phase of the male and female pen shells from October to February and such prolonged period of resting could be, in part, explainable by poor food condition in the study site. The present study first provided fundamental information on life history of A. pectinata, which can be usefully used in the management of this pen shell in Ulleung Island.en shells showed early development phase with small oogonia from January to April, although fem females exhibited ripe eggs in their follicular epithelium. In April, the oocyte diameter increased rapidly, and fully mature eggs appeared in May. First spawning males and females were observed in June as the surface water temperature reached 19.3°C and July (23.2°C) respectively. The spawning activity continued until the end of September. Histology indicated that spawning peak of the females in Ulleung Island was July to August. During October to January, most of the pen shells were in spent and resting stages. Our data suggested that A. pectinata is a summer spawner, and their annual gametogenesis is closely associated with the seasonal variation in the surface water temperature. Resting phase of the male and female pen shells from October to February and such prolonged period of resting could be, in part, explainable by poor food condition in the study site. The present study first provided fundamental information on life history of A. pectinata, which can be usefully used in the management of this pen shell in Ulleung Island.