scholarly journals The Migration, Culture, and Lifestyle of the Paleolithic Ryukyu Islanders

2020 ◽  
Author(s):  
Masaki Fujita ◽  
Shinji Yamasaki ◽  
Ryohei Sawaura
Keyword(s):  
Ryukyu Islands ◽  
Small Islands ◽  
Okinawa Island ◽  
Freshwater Crabs ◽  
Behavioral Adaptations ◽  
Human Dispersal ◽  
The Ryukyu Islands ◽  
A Chain ◽  
The Western Pacific ◽  
Human Fossils

Roughly 35,000 years ago, hunting-fishing-gathering people occupied the Ryukyu Islands of Japan, a chain of small-sized islands in the western Pacific. There are Paleolithic sites scattered over most of the relatively large islands, thereby suggesting an extensive human dispersal over the sea at least 30,000 years ago. Recent morphological and genetic studies of the human fossils found in this area revealed that Paleolithic occupants might have an affinity with the modern and prehistoric populations of Southeast Asia. Recent excavation of Paleolithic sediments at Sakitari Cave, Okinawa Island, provided a variety of shell artifacts, including beads, scrapers, and fishhooks, and evidence of seasonal consumption of aquatic animals, especially freshwater crabs. The Paleolithic Ryukyu Islanders’ culture and lifestyle, which made use of unique resources, demonstrate behavioral adaptations to living on relatively small islands.

Long-chain n-3 polyunsaturated fatty acids contained in liver and muscle tissues of Okinawan long-spine porcupinefish (Diodon holocanthus Linnaeus 1758)

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yutaka Tashiro
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Ryukyu Islands ◽  
Okinawa Island ◽  
Content Type ◽  
Muscle Tissues ◽  
The Ryukyu Islands ◽  
Total Fatty Acids ◽  
Long Chain

Purpose This study aimed to analyze the lipid content and fatty acid composition in the liver and muscle of a porcupinefish species inhabiting waters around the Ryukyu Islands to investigate their potential as a source of long-chain n-3 polyunsaturated fatty acids (LC-PUFAs). Design/methodology/approach Porcupinefish were collected along the Okinawa Island coast. The composition of fatty acids and cholesterol in both liver and muscle were analyzed using a gas chromatograph mass spectrometer. Findings The liver of Okinawan long-spine porcupinefish was rich in lipids whose content correlated to the proportion of liver/body weight. Fatty acid compositions in their liver and muscles were similar to each other. LC-PUFAs occupied 44% of total fatty acids, with docosahexaenoic acid (DHA) being the dominant (42%), whereas eicosapentaenoic acid occupied 2.4%. The liver contained 1,690 mg of cholesterol and 14.8 g of DHA per 100 g, whose proportion decreased in summer compared to other seasons (p = 0.036). Originality/value The liver of Okinawan long-spine porcupinefish, which has not yet been commercially used although its non-toxicity is claimed, can be an excellent source of LC-PUFAs, especially DHA, accentuating its potential in food supplements’ production.

On Two New Species of Geothelphusa Stimpson, 1858 (Decapoda, Brachyura, Potamidae) From the Ryukyu Islands, Japan

Crustaceana ◽  
1998 ◽  
Vol 71 (7) ◽  
pp. 778-784 ◽  
Author(s):  
J.-Y. Shy ◽  
Peter K.L. Ng
Keyword(s):  
New Species ◽  
Type Locality ◽  
Ryukyu Islands ◽  
Freshwater Crabs ◽  
Southern Japan ◽  
The Ryukyu Islands ◽  
Two New Species

AbstractTwo new species of potamid freshwater crabs of the genus Geothelphusa are described from the Ryukyu Islands in southern Japan. Although both G. shokitai sp. nov. and G. minei sp. nov. are allied to G. candidiensis (type locality Taiwan), they differ from that species and from each other in the form of their carapaces, ambulatory leg proportions, and structure of their male first pleopods.

scholarly journals Low-Frequency Earthquakes along the Ryukyu Islands Triggered by Teleseismic Earthquakes

2021 ◽  
Author(s):  
Ayumi Kinjo ◽  
Mamoru Nakamura
Keyword(s):  
Surface Waves ◽  
Low Frequency ◽  
Stress Sensitivity ◽  
Peak Ground Velocity ◽  
Ryukyu Islands ◽  
Plate Interface ◽  
Okinawa Island ◽  
Short Period ◽  
Ryukyu Arc ◽  
The Ryukyu Islands

Abstract Tremors and low-frequency earthquakes (LFEs), which occur in the plate interface, can provide useful information about the state of aseismic stress transfer in mega-earthquake fault zones. We estimated the distribution of stress sensitivity in the subducted plate interface by using triggered LFEs. Specifically, we detected LFEs in the Ryukyu Trench triggered by the surface waves of large teleseismic earthquakes by using the waveform records of broadband and short-period seismometers installed in the Ryukyu Arc. We selected a total of 45 teleseismic earthquakes with magnitudes of more than 7.5, which occurred between 2004 and 2017, for the analysis. We could detect the triggered LFEs for five teleseismic earthquakes. Then, we determined the hypocenters of LFEs by using the relative arrival times of LFEs for each station. The LFEs were distributed in the south of Okinawa Island and the Yaeyama area. Moreover, they were distributed around the source fault of the slow slip events. These were almost the same as the position of LFEs accompanying very low-frequency earthquakes (VLFEs). However, the epicenters of the triggered LFEs were concentrated near the locations of the most active LFE clusters accompanying VLFEs. This suggests that the sensitivity for inducing LFEs was higher near the most active clusters of the LFEs accompanying the VLFEs. The amplitudes of the triggered LFEs were proportional to the peak ground velocity of the surface waves. This indicates that the LFEs accompanying VLFEs are activated by stress acceleration in the Yaeyama and Okinawa areas and the triggered LFEs observed in these areas can be a result of the activation of the ambient tremors due to increased stress.

Redescription of a poorly known upogebiid mud shrimp Gebiacantha acanthochela (Sakai, 1967) and description of a new species of the genus from the Ryukyu Islands, Japan (Decapoda: Gebiidea)

Zootaxa ◽  
2020 ◽  
Vol 4881 (2) ◽  
pp. 307-322
Author(s):  
TOMOYUKI KOMAI
Keyword(s):  
New Species ◽  
New Caledonia ◽  
Original Description ◽  
Ryukyu Islands ◽  
Okinawa Island ◽  
The Ryukyu Islands ◽  
Female Holotype ◽  
Mud Shrimp ◽  
Japanese Waters ◽  
Amami Islands

Two species of the upogebiida mud shrimp genus Gebiacantha Ngoc-Ho, 1989, currently represented by 19 described species, are reported from the Ryukyu Islands, Japan. The first, G. acanthochela (Sakai, 1967), is redescribed in detail based on two female specimens from Amami Islands the second discovered since the original description, enabling better assessment of its diagnostic characters. The second, G. fortispinata n. sp., is described on the basis of a single female holotype from Okinawa Island. It appears closest to G. multispinosa Ngoc-Ho, 1994, known with certainty only from New Caledonia, but the proportionally narrower telson with a more deeply notched posterior margin and the distally unarmed pereopod 3 merus distinguish the new species from G. multispinosa. Three species of Gebiacantha, including G. sagamiensis Komai, 2017, are now known from Japanese waters.

A new hermit crab species of the genus Catapagurus (Crustacea: Decapoda: Anomura: Paguridae) from the Ryukyu Islands, southern Japan

Zootaxa ◽  
2009 ◽  
Vol 2211 (1) ◽  
pp. 57-68 ◽  
Author(s):  
TOMOYUKI KOMAI ◽  
MASAYUKI OSAWA
Keyword(s):  
New Species ◽  
Hermit Crab ◽  
Species Group ◽  
Shallow Waters ◽  
Ryukyu Islands ◽  
Crab Species ◽  
Okinawa Island ◽  
The Ryukyu Islands ◽  
The Family ◽  
A New Species

A new species of the pagurid hermit crab genus Catapagurus A. Milne-Edwards, 1880, C. insolitus, is described and illustrated based on specimens from shallow waters in Okinawa Island, the Ryukyus. It belongs to an informal species group characterized by the possession of blade-shaped ambulatory dactyli, and is morphologically most similar to C. kosugei (Asakura, 2001). However, the new species is unique within the genus in having a multispinose antennal acicle, rarely seen in species of the family Paguridae.

scholarly journals Pre-Bomb Marine Reservoir Ages in the Western Pacific

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1197-1206 ◽  
Author(s):  
Kunio Yoshida ◽  
Tatsuaki Hara ◽  
Dai Kunikita ◽  
Yumiko Miyazaki ◽  
Takenori Sasaki ◽  
...  
Keyword(s):  
Western Pacific ◽  
Ryukyu Islands ◽  
Japanese Archipelago ◽  
The Ryukyu Islands ◽  
The Mean ◽  
The Japanese Archipelago ◽  
University Museum ◽  
The University ◽  
Specific Correction ◽  
The Western Pacific

In this study, molluscan shells housed at the University Museum, the University of Tokyo, provided a new set of region-specific correction values (ΔR) for the western Pacific, in particular for the central part of the main islands in the Japanese Archipelago and the southwest islands of Japan. The values of 40 total samples were calculated from 11 regions. North of the main islands and in the Ryukyu Islands, the mean ΔR values showed comparatively small values, 5–40 14C yr; in the central part of the main islands, these values were 60–90 14C yr.

Founding of the Ming Dynasty and the Rise of the Ryukyu Kingdom

2016 ◽  
Author(s):  
Mamoru Akamine
Keyword(s):  
Ming Dynasty ◽  
East Asian ◽  
Trading Partner ◽  
Ryukyu Islands ◽  
Okinawa Island ◽  
Conventional View ◽  
The Ryukyu Islands ◽  
Tribute System ◽  
And Control ◽  
The Ming Dynasty

With the establishment of the Ming Dynasty, Emperor Hongwu announced a ban on sea travel to try and control wakō pirates. He established a tribute system whereby countries that accepted the Chinese emperor as sovereign could send tribute trade missions to and from China. Because the pirates frequented the Ryukyu Islands, Hongwu had a preference policy toward Ryukyu to obtain their help in controlling wakō pirates. Of the three domains dominating Okinawa Island, Chūzan emerged as China’s main trading partner, and this began the process of unifying the Ryukyu Kingdom. A number of Chinese merchants, traditionally known as “the Thirty-six Families” relocated to Ryukyu to facilitate tribute trade, though the author disputes the conventional view of this as a “gift” from China. By the end of the chapter, Ryukyu is poised to be a key player – a cornerstone – in the East Asian trade sphere.

Comanthus kumi, a new shallow-water comatulid (Echinodermata: Crinoidea: Comatulida: Comasteridae) from the Ryukyu Islands, Japan

Zootaxa ◽  
2012 ◽  
Vol 3367 (1) ◽  
pp. 261 ◽  
Author(s):  
YOSHIHISA FUJITA ◽  
MASAMI OBUCHI
Keyword(s):  
New Species ◽  
Coral Reefs ◽  
Shallow Water ◽  
Small Hole ◽  
Ryukyu Islands ◽  
Okinawa Island ◽  
The Ryukyu Islands ◽  
A New Species

A new species of the genus Comanthus A.H. Clark, 1908, is described on the basis of specimens collected from KumeIsland and Okinawa Island, the Ryukyu Islands, Japan. Comanthus kumi n. sp. is distinguished from all ten congeners byhaving extremely elongate arms exceeding 300 mm in length and the colouration in life. The new species concealed itswhole body in a crevice or small hole on coral reefs during the day and protruded only several elongate arms on the reef surface at night. This habit suggests that the new species is nocturnal.

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