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Occurrence of the Scyphomedusa Parumbrosa polylobata Kishinouye, 1910 in Suruga Bay, Japan
Hiroshi Miyake(1),(3)※, Dhugal J. Lindsay(1), Minoru Kitamura(1) ＆ Shuhei Nishida(2)

(1) Marine Biology and Ecology Research Program, Extremobiosphere Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC),
(2) Department of Marine Ecosystems Dynamics, Ocean Research Institute, University of Tokyo,
(3) Enoshima Aquarium,

Abstract:Aggregations of the scyphomedusa Parumbrosa polylobata were observed in the deep sea of Suruga Bay, Japan, using a crewed submersible and ROVs. This is the first record of P. polylobata off the Pacific coast of Japan. Parumbrosa polylobata was distributed in the benthopelagic layer (within 50 m of the seafloor) at 270-510 m bottom depth and was an active swimmer that was observed to feed on gelatinous zooplankton. Medium microbasic euryteles, one of four nematocyst types observed in the medusae, may play an important role in capturing gelatinous prey. Moribund individuals sank to the seafloor and became food for the benthos. Parumbrosa polylobata, which occurred in dense aggregations in the benthopelagic layer, seems to play an important role in matter transport from the pelagic to benthic communities.