scholarly journals A New Cave-Dwelling Eyeless Spider of the Genus Coelotes (Araneae: Amaurobiidae) from Okinawa Island, the Ryukyu Islands, Japan, with Notes on Possible Parthenogenesis

2000 ◽  
Vol 49 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Matsuei Shimojana ◽  
Moritaka Nishihira
Keyword(s):  
Ryukyu Islands ◽  
Okinawa Island ◽  
The Ryukyu 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.

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.

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.

scholarly journals Reconstruction of ocean environment time series since the late nineteenth century using sclerosponge geochemistry in the northwestern subtropical Pacific

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ryuji Asami ◽  
Taketo Matsumori ◽  
Ryuichi Shinjo ◽  
Ryu Uemura ◽  
Yuki Miyaoka ◽  
...  
Keyword(s):  
Nineteenth Century ◽  
Time Series ◽  
Atmospheric Aerosols ◽  
Late Nineteenth Century ◽  
Ryukyu Islands ◽  
Okinawa Island ◽  
Carbon And Oxygen Isotope ◽  
The Ryukyu Islands ◽  
Decadal Variations ◽  
Late Nineteenth

AbstractThe geochemistry of calcifying marine organisms is an excellent proxy for reconstructing paleoceanographic history, but studies of hypercalcified demosponges (sclerosponges) are considerably fewer than those of corals, foraminifers, and bivalves. For this study, we first generated near-annual resolved stable carbon and oxygen isotope (δ13C and δ18O) and element/Ca ratios (Sr/Ca, Ba/Ca, Pb/Ca, U/Ca) time series for 1880–2015 from sclerosponge samples (Acanthochaetetes wellsi) collected at Miyako Island and Okinawa Island in the Ryukyu Islands of southwestern Japan. The δ13C records exhibited a typical variation of anthropogenically derived Suess effects, demonstrating that the rates of decrease of –0.0043‰/year before 1960 and – 0.024‰/year after 1960 in the northwestern subtropical Pacific were respectively similar to and about 1.4 times higher than those of the Caribbean Sea in the tropical Atlantic. Spectral analysis of the δ18O time series revealed significant periodicity of approximately 2, 3, 6.5, 7–10, and 20–30 year/cycle, indicating that sea surface conditions in the southern Ryukyu Islands had been dominated by interannual and decadal variations in temperature and seawater δ18O since the late nineteenth century. The Sr/Ca and U/Ca ratios for the species A. wellsi (high-Mg calcite) might not be a robust proxy for seawater temperatures, unlike Astrosclera willeyana and Ceratoporella nicholsoni sclerosponges (aragonite). An evident increasing Pb/Ca trend after 1950 found in the samples is probably attributable to Pb emissions from industrial activities and atmospheric aerosols in eastern Asian countries. The Ba/Ca variations differ greatly among sampling sites, which might be attributable to the respective local environments. This evidence demonstrates that more high-resolution age determinations and geochemical profilings enable delineation of secular variations in ocean environments on annual and interannual timescales. Results of our study suggest that if sclerosponges living in deeper ocean environments are collected, spatial and vertical oceanographic variations for the last several centuries will be reconstructed along with coral proxy records.

A new hermit crab species of the genus Catapaguroides A. Milne-Edwards & Bouvier (Crustacea: Decapoda: Anomura: Paguridae) from the Ryukyu Islands, Japan, and additional record of C. foresti McLaughlin

Zootaxa ◽  
2010 ◽  
Vol 2690 (1) ◽  
pp. 32
Author(s):  
TOMOYUKI KOMAI ◽  
YUSUKE YAMADA ◽  
NAOKI SHIRAKAWA
Keyword(s):  
Ryukyu Islands ◽  
Crab Species ◽  
Single Male ◽  
Okinawa Island ◽  
Male Specimen ◽  
General Morphology ◽  
The Ryukyu Islands ◽  
Submarine Cave ◽  
The Right ◽  
Subjective Synonym

Two species of the pagurid genus Catapaguroides A. Milne-Edwards & Bouvier, 1892, C. longior n. sp. and C. foresti McLaughlin, 2002, are reported herein. The new species is described on the basis of a single male specimen collected from a submarine cave at Onna Village, Okinawa Island, Ryukyu Islands, at a depth of 30 m. In general morphology, it is most similar to C. inermis de Saint Laurent, 1968, but is readily distinguished from that species by the elongate antennal acicle and the broad carpus of the right cheliped. Examination of newly collected specimens from Japan led us to conclude that C. kasei Osawa & Takeda, 2004 is a junior subjective synonym of C. foresti McLaughlin, 2002. An emended key to the presently recognized species of the genus is provided.

A new squat lobster species of the genus Munida (Decapoda, Anomura, Munididae) from the deep-sea off the Ryukyu Islands, Japan

Crustaceana ◽  
2017 ◽  
Vol 90 (7-10) ◽  
pp. 969-979
Author(s):  
Tomoyuki Komai
Keyword(s):  
New Species ◽  
Deep Sea ◽  
The Philippines ◽  
Ryukyu Islands ◽  
Single Male ◽  
Okinawa Island ◽  
Male Specimen ◽  
Squat Lobster ◽  
The Ryukyu Islands ◽  
Japanese Waters

Munida michaeli, a new species of deep-sea squat lobster (Munididae), is described and illustrated on the basis of a single male specimen collected off Okinawa Island, Ryukyu Islands, Japan, at depths of 641-650 m. It closely resemblesM. sacksiMacpherson, 1993 known with certainty only from the Philippines, but different spination of the carapace dorsum and the greatly reduced armature of the flexor margins of the ambulatory dactyli distinguish the new species from the latter. With the addition of the present new species, 41 species ofMunidaLeach, 1820 are now known from Japanese waters.

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