The Spawning Period of the Sea Cucumber Stichopus japonicus in the North Yellow Sea

摘要

The spawning period of sea cucumber (stichopus japonicus) has been studied based on the investigation of the gonadal index, primary branch diameter of gonad and spawning in the North Yellow Sea. The results are as following: direct1 The sea cucumber began to spawn when water temperature of the surface was about 20degC in the iddle of July. The spawning period was about two months from the middle of July.