著者
Watanabe Yasunori Saeki Hiroshi Hosking Roger J.
出版者
Cambridge University Press
雑誌
Journal of Fluid Mechanics (ISSN:00221120)
巻号頁・発行日
vol.545, pp.291-328, 2005
被引用文献数
125

The large-scale vortex structures under spilling and plunging breakers are investigated, using a fully three-dimensional large-eddy simulation (LES). When an overturning jet projecting from the crest in a breaking wave rebounds from the water surface ahead, the vorticity becomes unstable in a saddle region of strain between the rebounding jet and a primary spanwise vortex, resulting in spanwise undulations of the vorticity. The undulations are amplified on a braid in this saddle region, leading to a vortex loop with counter-rotating vorticity. This vortex loop consequently envelops adjacent primary vortices, to form a typical rib structure. This rib component (the stretched vortex loop) in the large-scale vortex structure, which intensifies in the strains associated with the multiple primary vortices generated throughout the splash-up cycle, appears to be the previously found obliquely descending eddy.
著者
Kakui Keiichi Fujita Yoshihisa
出版者
Cambridge University Press
雑誌
Journal of the Marine Biological Association of the United Kingdom (ISSN:00253154)
巻号頁・発行日
vol.103, 2023
被引用文献数
1

We describe a new sea spider species, Pantopipetta hosodai sp. nov., based on one juvenile female collected from a submarine cave ('Akumanoyakata' Cave) in Shimojijima Island, Miyako Island Group, Ryukyu Islands, southwestern Japan. It was collected from the second slope zone of the cave, 80-100 m from the entrance, no light, low salinity and with rocky substrate. This is the first record globally of a Pantopipetta species from a submarine cave and anchialine environment. Pantopipetta hosodai sp. nov. resembles Pantopipetta auxiliata, Pantopipetta lenis and Pantopipetta oculata in having auxiliary claws, but differs from them in having a palp with three short distal articles, lateral processes without dorsodistal tubercles, coxae 1 and 3 of legs 1-3 each with one long dorsal tubercle and one dorsodistal tubercle bearing a seta on each femur. Features of the palp appear to delineate two species groups in Pantopipetta, i.e. (1) those having four small distal articles, and a small, basal palp article between the lateral cephalon process and longest palp article (eight-articulate palp) and (2) those having three small distal articles, and lacking the small basal article (six-articulate palp), but further detail examination of the described species is needed. We discuss the diagnostic characters separating Pantopipetta and Austrodecus and the generic affiliation of Austrodecus aconae. Few pycnogonids from marine or anchialine caves have been identified to species, and it is generally unknown whether cave-dwelling pycnogonids tend to be troglobites.
著者
G.S. Kirk
出版者
Cambridge University Press
巻号頁・発行日
1985
著者
Kakui Keiichi Shimada Daisuke
出版者
Cambridge University Press
雑誌
Journal of Helminthology (ISSN:0022149X)
巻号頁・発行日
vol.96, pp.e33, 2022
被引用文献数
7

We report the first mermithid nematode found to be parasitic in a marine tanaidacean crustacean. Ten host tanaidaceans were collected from 52 m depth in Otsuchi Bay, Iwate, Japan, northwestern Pacific, and identified as a species in the tanaidid genus Zeuxo Templeton, 1840. Nematodes occurred in the host’s body cavity; in one case, at least two individuals inhabited a single host. We provide a brief description and illustrations of the morphology of the nematode. In a phylogenetic reconstruction based on the 18S rRNA gene, the nematode nested in a clade otherwise containing mermithids from terrestrial or freshwater hosts, showing an expansion in host utilization in Mermithidae Braun, 1883 from terrestrial/freshwater hosts to a marine organism.
著者
Ervand Abrahamian
出版者
Cambridge University Press
巻号頁・発行日
2018
著者
SENGOR A. M. C.
出版者
Cambridge University Press
雑誌
The Tectonic evolution of Asia
巻号頁・発行日
pp.486-640, 1996
被引用文献数
1