抄録
The mesopelagic layer is known as “twilight zone” and is situated between the euphotic and aphotic layers, ca. 200-1000 m. As the mesopelagic ecosystem is fuelled by organic matter produced in the euphotic layer, some organisms are adapted to sense and feed on sinking particles from the euphotic layer. They are often inactive in dimlit and cold mesopelagic layer compared with organisms in the sunlit and warm epipelagic layer. On the other hand, many mesopelagic zooplankton and micronekton carry out vertical migration to the epipelagic layer for foraging. In this study, the structure of the mesopelagic ecosystem and dynamic interaction between epipelagic and mesopelagic ecosystems are described.