Observation of a Gelatinous Octopod, Haliphron atlanticus, along the Southern West Mariana Ridge: A Unique Cephalopod of Continental Slope and Mesopelagic Communities

Figure 1

Location of the YK17-10 study area in the western North Pacific (a), the bottom topography of the southern West Mariana Ridge and Mariana Trench region showing the study area where underwater observations by the Shinkai 6500 submersible were made (small squares in (a, b)) along the west side of the ridge (b), and vertical profiles of bottom depth along transects (dashed lines in (b)) extending from the trench northward along the ridge (c; Transect A) and crossing the ridge longitudinally along the northern edge of the study area that includes the shallowest seamount in that part of the ridge (d; Transect B), with the location where the gelatinous giant octopod, Haliphron atlanticus, was seen, shown with stars. A diagram of the approximate horizontal directions and locations of the dive tracks of the submersible inside the study area square is shown in the inset (d). Color in (b) indicates deeper (blue/dark) and shallower (yellow-orange/lighter) depths.