オンケア科カイアシ類のマリンスノーに対する摂食：Video Plankton Recorderによる現場観察

抄録

The Video Plankton Recorder (VPR) is a non-invasive optical sampling system that enables in situ observations of associations between zooplankton and fragile marine snow aggregates. Here we employed the VPR to observe attachment and feeding behavior of oncaeid copepods to marine snow in the field. VPR surveys were conducted in the surface waters (0–100 m) of the Kuroshio region off Shikoku during February 2011. We recorded images of oncaeid copepods being attached to discarded and occupied appendicularian houses, and amorphous aggregates in the area. These observations suggest that oncaeid copepods utilize these particles as food sources, since they are primarily substrate feeders. In particular, more than 80％of attached individuals were found on discarded appendicularian houses, indicating a close trophic coupling between the oncaeids and the houses. The implications for aggregate colonization behavior of oncaeid copepods are also discussed on the basis of the VPR observations.