scholarly journals Taxonomy and Natural History of the Funnel-Web Spider Genus Macrothele (Araneae : Hexathelidae : Macrothelinae) in the Ryukyu Islands (Japan) and Taiwan

1998 ◽  
Vol 3 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Matsuei Shimojana ◽  
Joachim Haupt
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Masahiko Muraji ◽  
Norio Arakaki ◽  
Shigeo Tanizaki

The phylogenetic relationship, biogeography, and evolutionary history of closely related two firefly species,Curtos costipennisandC. okinawanus, distributed in the Ryukyu Islands of Japan were examined based on nucleotide sequences of mitochondrial (2.2 kb long) and nuclear (1.1-1.2 kb long) DNAs. In these analyses, individuals were divided among three genetically distinct local groups,C. costipennisin the Amami region,C. okinawanusin the Okinawa region, andC. costipennisin the Sakishima region. Their mtDNA sequences suggested that ancestralC. costipennispopulation was first separated between the Central and Southern Ryukyu areas, and the northern half was then subdivided betweenC. costipennisin the Amami andC. okinawanusin the Okinawa. The application of the molecular evolutionary clocks of coleopteran insects indicated that their vicariance occurred 1.0–1.4 million years ago, suggesting the influence of submergence and subdivision of a paleopeninsula extending between the Ryukyu Islands and continental China through Taiwan in the early Pleistocene.


2007 ◽  
Vol 55 (1) ◽  
pp. 9 ◽  
Author(s):  
Dinesh Rao ◽  
Ken Cheng ◽  
Marie E. Herberstein

A long-running debate in the spider literature concerns the function of the extra silk decorations in some spider webs. These decorations are appended to the web and constitute a highly visible signal, which is inconsistent with the trend towards web invisibility. Despite the sustained attention of researchers, the exact function of these decorations is yet to be understood. While most studies have focussed on testing particular hypotheses, there has been a dearth of natural history data regarding web decorations in field conditions. In this study we present baseline data regarding the influence of seasonality, microhabitat characteristics and ecology on the presence of web decorations in an Australian orb web spider, Argiope keyserlingi. In particular, we show that there is preference among spiders to build their webs between bushes and to face the south-east, but this preference does not influence decoration building.


Author(s):  
Ryosuke Fujita ◽  
Kazuhisa Goto ◽  
Yasufumi Iryu ◽  
Tomoya Abe

Abstract Huge tsunami waves have repeatedly bombarded the southern end of the Ryukyu Islands (Miyako and Yaeyama Islands, southwestern Japan) at several-hundred-year intervals. Therefore, clarifying the islands’ paleotsunami history is important for risk assessment. Nevertheless, discrepancies of paleotsunami histories exist among regional studies of tsunami boulders and sandy tsunami deposits. Radiocarbon ages of tsunami boulders indicate that tsunami events of the last 2400 years have occurred every 150–400 years, most recently the historical 1771 Meiwa tsunami. Sandy tsunami deposits at Yaeyama Islands show that four tsunami events of the last 2000 years struck the islands at approximately 600-year intervals. Sandy tsunami deposits of the Miyako Islands have been studied only rarely. Therefore, studying sandy tsunami deposits in the Miyako Islands is crucially important for clarifying the paleotsunami history of this region. We conducted a trench survey on Minna Island, located among the westernmost Miyako Islands, which revealed two sandy tsunami deposits under a coral tsunami boulder transported by the 1771 tsunami. The upper tsunami deposit was likely deposited by the 1771 tsunami, as inferred from stratigraphic correlation to the tsunami boulder. However, the lower tsunami deposit was probably deposited 700–1000 years ago, which is consistent with the age range of the paleotsunami reported for Yaeyama Islands. Because sandy tsunami deposits found in this and earlier studies are thick and deposited at high elevation and far inland, these are useful markers of large tsunami events similar to the 1771 event. However, the reported tsunami boulders of various sizes are deposited along the coast and reefs: they can be formed not only by large tsunami events but also by small ones. It is noteworthy that each tsunami deposit is coarse and thick (40–48 cm) relative to the island elevation (about 12 m maximum, 7 m above the mean sea level at the study site). By assuming that tsunamis have affected this region repeatedly during the past few thousand years at around 600-year intervals, tsunamis might have been important geomorphic agents for building up small reef-surrounded islands such as Minna Island.


Author(s):  
Mamoru Akamine

This English translation of an Okinawan scholarly voice provides a compelling new picture of the role played by the Ryukyu Kingdom in pre-modern East Asia. Mamoru Akamine first examines the early history of the Ryukyu Islands, then goes on to detail the vital role the Ryukyu Kingdom played in a vibrant East Asian trade sphere, which centered on Ming China, and connected what we now call Japan, Korea, and China with Southeast Asia. Despite the successful 1609 invasion of Ryukyu by Japan’s Satsuma domain, the kingdom was able to maintain quasi-independence for two and a half more centuries by skillfully mediating between Japan and China, who rarely dealt directly with each other. The narrative draws to a close as Akamine describes the steps leading to Ryukyu’s eventual annexation by Japan in 1879 as Okinawa Prefecture. What distinguishes this book is Akamine’s deployment of Chinese and Korean sources, depicting an East Asia made up of many moving parts, not just nation states pursuing their own interests. Yet these same sources allow him to zoom in on the small, telling particulars that make up that big picture. The reader can understand as never before the complexity of Ryukyu’s relations with its neighbors.


2020 ◽  
Vol 43 ◽  
Author(s):  
Hannes Rakoczy

Abstract The natural history of our moral stance told here in this commentary reveals the close nexus of morality and basic social-cognitive capacities. Big mysteries about morality thus transform into smaller and more manageable ones. Here, I raise questions regarding the conceptual, ontogenetic, and evolutionary relations of the moral stance to the intentional and group stances and to shared intentionality.


Sign in / Sign up

Export Citation Format

Share Document