Tsushima Island Research Articles

Severe hypofibrinogenemia in patients bitten by Gloydius tsushimaensis in Tsushima Island, Nagasaki, Japan, and treatment strategy

Gloydius tsushimaensis is an endemic species inhabiting only Tsushima, a remote Japanese island, and is a distinct species from Gloydius blomhoffii widely distributed throughout mainland Japan and Gloydius brevicaudus and Gloydius ussuriensis which are geographically distributed in South Korea. This is the first multicenter retrospective study of G. tsushimaensis bites in Japan. A study of seventy-two patients who visited the former Izuhara Hospital, the former Naka Tsushima Hospital, Tsushima Hospital, and Kamitsushima Hospital during the fourteen years from January 1, 2005, to December 31, 2018, revealed the typical clinical characteristics of G. tsushimaensis bites. Five out of seventy-two cases (6.9%) showed severe hypofibrinogenemia, in which fibrinogen levels were below 100 mg/dl, which is an unreported clinical finding for G. blomhoffii bites. Generally, when fibrinogen levels are lower than 100 mg/dl, the bleeding risk increases, and it is perilous. Severe hypofibrinogenemia cases did not improve after G. blomhoffii antivenom administration. Additionally, all five cases had disseminated intravascular coagulation, and there were two cases of acute kidney injury and one death. five cases had a median maximum creatine kinase level of 5171 IU/l (Interquartile range: 4992–41,310). Although the mechanism is not precise, coagulation tests showed that the G. tsushimaensis venom contains a thrombin-like enzyme. Based on this research, we created an algorithm for the treatment of G. tsushimaensis bites and unified the treatment methods used on the island.

River Water Quality and Basin Environment on Islands in Nagasaki Prefecture: Mainly in Tsushima, Iki and Hirado Islands

River Water Quality and Basin Environment on Islands in Nagasaki Prefecture: Mainly in Tsushima, Iki and Hirado Islands

Genetic Diversity and Genetic Structure of the Wild Tsushima Leopard Cat from Genome-Wide Analysis.

Simple SummaryThe Tsushima leopard cat, Prionailurus bengalensis euptilurus, is a small regional population of the Amur leopard cat and is only found on Tsushima Island in Japan. A breeding program will require adequate information on parentage, kinship, and inbreeding for this population. Hence, there is an urgent need to develop this information in order to conserve the population and its genetic diversity. We performed GRAS-Di analysis to investigate the genetic diversity and genetic structure of the Tsushima leopard cat. We identified between 133 and 158 single-nucleotide polymorphism (SNP) markers in three different genotyping methods. These SNP markers can be used in identification of individuals and parentage. In addition, structure analysis using these markers demonstrated the similar genetic composition of the samples from 48 Tsushima leopard cats, and indicated Tsushima leopard cats have no subpopulations. We have provided genetic markers that are useful for conservation of the Tsushima leopard cat, such as individual identification and parentage. Moreover, we have also clarified units for conservation of the Tsushima leopard cat population from structure analysis.The Tsushima leopard cat (Prionailurus bengalensis euptilurus) lives on Tsushima Island in Japan and is a regional population of the Amur leopard cat; it is threatened with extinction. Its genetic management is important because of the small population. We used genotyping by random amplicon sequencing-direct (GRAS-Di) to develop a draft genome and explore single-nucleotide polymorphism (SNP) markers. The SNPs were analyzed using three genotyping methods (mapping de novo, to the Tsushima leopard cat draft genome, and to the domestic cat genome). We examined the genetic diversity and genetic structure of the Tsushima leopard cat. The genome size was approximately 2.435 Gb. The number of SNPs identified was 133–158. The power of these markers was sufficient for individual and parentage identifications. These SNPs can provide useful information about the life of the Tsushima leopard cat and the pairings and for the introduction of founders to conserve genetic diversity with ex situ conservation. We identified that there are no subpopulations of the Tsushima leopard cat. The identifying units will allow for a concentration of efforts for conservation. SNPs can be applied to the analysis of the leopard cat in other regions, making them useful for comparisons among populations and conservation in other small populations.

Environments, spatial structures, and species competitions: determining the impact of yellow-legged hornets, Vespa velutina, on native wasps and bees on Tsushima Island, Japan

Invasive alien species (IAS) can have serious negative impacts on native species in invaded areas. Researchers attempting to measure the impacts of IAS on native species at a landscape level often face challenges though, because the effects of environmental gradients and spatial autocorrelation on population structures are difficult to separate. To evaluate the impacts of IAS, we used spatial filtering and variation partitioning to remove environmental and spatial autocorrelation effects from abundance data for seven native insect species and one IAS, Vespa velutina, on the island of Tsushima, Japan. Here we show that negative correlations among Vespa species persisted after removal of environmental and spatial autocorrelation effects. The fact that alien V. velutina and native Vespa mandarinia japonica showed the strongest negative correlations with other native Vespa species suggested that there were strong competition or/and predation among Vespa species. The ongoing expansion of V. velutina since its incursion indicates that this species may impose strong negative impacts on other Vespa species, but it is possible that the slow expansion of V. velutina to the southern part of Tsushima is due to the presence of other Vespa species that function as a biological barrier. Since most IAS showed spatially structured distributions, especially at the initial stage of the incursion, spatial filtering is a promising tool to evaluate IAS impacts on native species.

Campaign of Second Pacific Squadron and the Battle of Tsushima in 1905 in Publications of “Kuban Regional Vedomosti”

The fragments of essays of the newspaper "Kuban Regional Vedomosti", which was published in Yekaterinodar at the beginning of the 20th century are provided in the article. It is noted that during this period, printed periodicals were the only source of information about the events of the Russan-Japanese War (1904-1905), accessible to wide strata of society living in various regions of the Russian Empire. The presented results of the analysis of articles, essays and notes about the Battle of Tsushima and the activities of Admiral Z. P. Rozhestvensky allow us to judge what information was disseminated in Russian society through the periodical press. The author of this article, based on the publications of the newspaper “Kuban Regional Vedomosti”, explores the opinions of Russian and foreign military experts on the strategies and tactics of the Russian military command. The main attention is paid to the analysis of articles that describe the movements of the Russian naval squadron from the Baltic Sea to Vladivostok and the largest naval battle of the beginning of the 20th century near Tsushima Island. The relevance of the problems is due to the fact that in historical science there is no consensus on the causes of military defeat, as well as on the role of Z. P. Rozhestvensky. The degree of information content of the publications of the newspaper “Kuban Regional Vedomosti” about the events of the Russan-Japanese War is estimated, the pro-government ideological orientation of this periodical is illustrated with concrete examples.

Molecular and Morphological Diversity of Heterodesmus Brady and Its Phylogenetic Position within Cypridinidae (Ostracoda)

Ostracod genus Heterodesmus Brady, 1866 is known thus far to contain only three species: H. adamsii Brady, 1866; H. apriculus Hiruta, 1992; and H. naviformis (Poulsen, 1962). This genus has been recorded from the Sea of Japan, and the coastal areas of Thailand and Vietnam. The main generic character is the presence of antero-dorsal and postero-dorsal tube-like processes on the rostrum on both valves. The three species mostly differ in the shell lateral projections. Their relationship and the position of Heterodesmus within family Cypridinidae are poorly understood, partly due to the lack of publication of DNA data so far. We study Heterodesmus collected from several localities in the Northwest Pacific, namely Tsushima and Iki Islands in Japan and Maemul Island in Korea. Besides morphological characters, we also use two mitochondrial markers (16S rRNA and mtCOI) and three nuclear regions (18S rRNA, 28S rRNA, and internal transcribed spacer - ITS) in the samples to detect the biodiversity of this genus. Our phylogenetic tree based on molecular data coupled with morphology reveals the presence of two species, H. adamsii and H. apriculus. We report on their morphological variability, molecular diversity, and phylogenetic position within Cypridinidae based on 16S, 28S and 18S rRNAs, and provide a taxonomic key for all living genera of this family. For the first time, we give an overview of the intrageneric and intrafamily DNA distances of the above markers for the entire subclass Myodocopa.

First Report of the Dinoflagellate Genus Effrenium in the East Sea of Korea: Morphological, Genetic, and Fatty Acid Characteristics

Most species in the family Symbiodiniaceae are symbiotic partners to invertebrate and protist hosts, but a few live freely in water columns. Here, a free-living dinoflagellate was isolated from the waters off the Dokdo Islands in the East Sea of Korea. Morphological and molecular analyses show this isolate belongs to Effrenium voratum. Prior to the present study, E. voratum had been reported to live in the waters in the temperate latitudes in the western North Pacific, the southwest Western Pacific, the eastern North Pacific, the eastern Atlantic, and the Mediterranean Sea. To our knowledge, this is the highest latitude in the western North Pacific, where E. voratum has been reported. This report extends the known range of this dinoflagellate to the temperate waters of the western North Pacific Ocean. The sequence of the D1/D2 region of the large subunit ribosomal DNA (LSU rDNA) was identical to E. voratum found in Jeju Island, Korea, Tsushima Island, Japan, and Cook Strait, New Zealand, suggesting this species is cosmopolitan. However, it was different by 1 bp from those found in Blanes, Spain and Santa Barbara, USA. In the phylogenetic tree built on the basis of the LSU (D1-D2) rDNA region sequences, this dinoflagellate was clustered within a clade, including all the other E. voratum strains. Morphological characteristics were like those of strains found in the waters of Jeju Island. This is the first report conducted on the fatty acid profile of fully characterized E. voratum. Importantly, the isolate possessed a high ratio of long-chain omega-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to total lipid. This dinoflagellate could be a candidate for commercial applications, such as aquaculture feed and essential omega-3 PUFA productions.

対馬の観光における他者イメ-ジの形成 -ミドルマンを中心として-

본고는 쓰시마 관광이 한일 두 나라 관계에 지속적으로 좌우되는 구조에서 관광을 통해 형성되는 타자 이미지에 관해 관광의 액터에 초점을 맞추고 문화인류학적으로 분석하려고 한다. 쓰시마는 저조한 국내 관광객을 대신하여 한국인 관광객 유치에 힘을 썼다. 그 결과 2000년에 정기 선박이 취항하게 되자 많은 관광객이 방문하게 되었다. 쓰시마는 특정 국가의 관광객이 많이 찾는 곳으로 유명하다. 한국인 관광객의 증가에 따라 쓰시마에 거주하면서 일하는 한국인도 증가했다. 본고에서는 이러한 쓰시마 관광에 종사하는 한국인과 연계하는 일본인 관광 관계자, 섬 외부에서 이주해 와서 관광 관련 산업에 종사하는 일본인이주자를 미들맨으로 규정하고 이들을 대상으로 상호 이미지를 어떻게 형성하고 있는지를 분석한다. 한일 미들맨들은 쓰시마의 관광 사업에 대한 인식을 바꾸고 일본과 한국을 연결시켜주는 역할을 하고 있다. 한편으로 그 들의 상호 이미지가 한일 국민 국가의 틀에서 벗어나지 못한 것도 부정할 수 없다.

Efforts to Reduce Volume of Floating Marine Litter in Isolated Tsushima Island and Milliplastics

Efforts to Reduce Volume of Floating Marine Litter in Isolated Tsushima Island and Milliplastics

Origin and water depth of a newly identified seep carbonate and paleoecology of Bathymodiolus in the Miocene Taishu Group, southwestern Japan

The Fukuzaki Limestone is a small limestone lens embedded in siliciclastic Taishu Group rocks on Tsushima Island in the southwestern Japan Sea. A fossil assemblage in this limestone consisting of the bivalve mollusc Bathymodiolus sp. (Bathymodiolinae) was previously inferred, on the basis of the limestone's isolated lenticular occurrence and the chemosynthetic nature of modern Bathymodiolinae, to rely on chemosynthetic production, but conclusive evidence was not provided. Carbon, nitrogen, oxygen, and sulfur isotope ratios in the limestone and its host rock mudstone were measured to clarify the paleoecology of the fossil assemblage and the formation environment of the limestone. The low δ13C (−39.8‰ to −31.7‰) and δ18O (−13.8‰ to −11.9‰) values of carbonate of the limestone lens strongly suggest that the limestone is composed of authigenic carbonate rock precipitated from bicarbonate derived from anaerobic oxidation of biogenic or thermogenic methane. The fossil assemblage in the limestone lens is consistent with a chemosynthesis-based animal assemblage harboring thioautotrophic (sulfur-oxidizing) symbionts, and the low δ13C and δ34S values of total organic carbon and sulfide sulfur, respectively, in the limestone lens and mud layers suggest that they reflect chemosynthetic production using hydrogen sulfide derived from anaerobic methane oxidation by microbes. Furthermore, the stratigraphic position of the lens in the upper part of the Lower Unit of the Taishu Group indicates that it was precipitated at a water depth >800 m (deeper than the lower middle bathyal zone). These findings indicate that a deep-sea basin locally supplied with methane had already formed in the southwestern Japan Sea by rapid subsidence during the opening stage of the Japan Sea (16–17 Ma).

Variation in flash speed of Japanese firefly,Luciola cruciata(Coleoptera: Lampyridae), identifies distinct southern “quick‐flash” population on Goto Islands, Japan

AbstractLuciola cruciata, a bioluminescent firefly endemic to Japan, communicates with species‐specific flashing patterns. Previous studies reported that flying males possess three distinct flashing frequencies: slow (4 s), intermediate (3 s) and fast (2 s). Our study focused on geographical variations in flashing patterns in the northwestern part of the Kyushu region of southern Japan (including its isolated islands) and their relationship to the mitochondrialCOIIregion of firefly DNA. We found that “quick‐flash (1 s)” fireflies occur in the Goto Islands, at the western tip of Kyushu, and that, although they possess a unique haplotype, they do not differ much genetically from “fast‐flash” fireflies inhabiting mainland Kyushu. In contrast, although fireflies inhabiting the Tsushima and Iki Islands also possess a unique haplotype, their flashing patterns were the same (fast‐flash) as fireflies inhabiting mainland Kyushu. We determined that flash patterns ofL. cruciatain Japan should be classified according to four flashing patterns: slow, intermediate, fast and quick.

Estimation of artificial reef effect range in the waters of Tsushima Islands, Nagasaki, Japan

Estimation of artificial reef effect range in the waters of Tsushima Islands, Nagasaki, Japan

Rediscovery of Otters on the Tsushima Islands, Japan by Trail Cameras

Otters are thought to be extinct in Japan, although they were widely distributed there until the early 20th century. Records of otters on Tsushima Islands, located between Kyushu and the Korean Peninsula, were found only in two sources from about 1735 and 1809, and there has been no evidence of their existence since the middle of 19th century until now. We set infrared trail cameras to monitor the Tsushima leopard cat on the northern island of Tsushima. Otter(s) were recorded by these cameras four times, on February 6 and July 16, 2017 in the Tanohama area and on October 1 and 3, 2017 in the Sago area of the island. This is the first record of an otter in Japan since the last record was made in Kochi Prefecture in 1979. The otters recorded on the islands could not be identified to species level based on the footage feed from the trail cameras. Based on historical information about otters in Tsushima and the surrounding areas, the origin of the otters is thought to have been natural dispersal from the Korean Peninsula, the nearest habitat of the Eurasian otter.

A new species and a new record of the genus Acalypta (Hemiptera: Heteroptera: Tingidae) from Japan.

Two moss-feeding species of the lace bug genus Acalypta Westwood, 1840 (Hemiptera: Heteroptera: Tingidae), are reported from Japan. Acalypta cooleyi Drake, 1917, is recorded for the first time from Japan (Honshu), and a new species, A. pallidicoronata sp. nov., is described from Tsushima Island.

Phytochemical characterization of Rosa multiflora Thunb. (Rosaceae) in Japan and South Korea, with a focus on the bioactive flavonol glycoside 'multiflorin A'.

Dried achene or anthocarpous accessory fruits of Rosa multiflora Thunb., Rosae fructus ("Eijitsu" in Japanese), have been used in clinical practice to improve constipation within traditional Japanese medicine. Recently, it has been claimed that the efficacy of this crude drug is decreasing, and multiflorin A, the purgative component, was not detected within the tested samples. In order to clarify the causes of this issue, we investigated Rosa section Synstylae (Rosaceae), including R. multiflora, growing in Japan and South Korea with a focus on the secondary metabolite, multiflorin A. We recognize that there are two chemotypes based on the presence (Type I) or absence (Type II) of multiflorin A. Type I contains quercitrin, multinoside A, multiflorin B, and multinoside A acetate as major index compounds. Type II contains hyperin, isoquercitrin, quercetin 3-O-glucuronide, and 3'-methoxy-isoquercitrin as the major index compounds. The chemotype of Rosa section Synstylae (Rosaceae) plants collected in Japan (excluding Tsushima Island) were all classified as Type I with exception of two species, R. luciae and R. sambucina. On the other hand, both Type I and Type II were detected within Rosae fructus obtained from R. multiflora collected in South Korea and Tsushima Island, Japan. The results indicate that Rosae fructus from R. multiflora (Type I) from Japan, excluding Tsushima Island, should be employed clinically, which we describe as purgative.

A study on the location of storehouse from the aspect of ownership in Tsushima Island, Nagasaki Prefecture

In this research, we aimed to analyze the locations of storehouses from the perspective of ownership, and to clarify the location profile of storehouses on Tsushima Island, Nagasaki Prefecture, for villages not previously investigated. The study area was Tsushima, a detached island in Nagasaki Prefecture. The areas surveyed surveyed were five villages, namely Tanohama, Waita, Yokoura, Shimobaru, and Kashine. As a result of the survey, we were able to clarify the location and ownership of storehouses in the surveyed settlement. Various storehouse ownership forms were seen, such storehouses owned near the main building and those located far away. In response to the survey results in this study, it is inferred that storehouses tend to be built on unusable land around the village. It was also inferred that the location of storehouses is affected by land use and land ownership in the village. The results of this project contribute to the development of storehouse research in Japan and abroad, emphasize the value of Tsushima's disappearing storehouses, and also contributes to the preservation and utilization as a cultural property of cultural landscape elements.

Genetic analysis of Taishu horses on and off Tsushima Island: Implications for conservation.

ABSTRACTTaishu horses are a native Japanese breed, of which only 41 individuals remained on Tsushima Island in 2018. Their genetic diversity is considered lower than that of other Japanese native horse breeds; thus, it needs to be investigated for sustainable conservation of this breed. Historical records revealed that several Taishu individuals were released areas off-Tsushima Island in mid-1980s. At present, Taishu horses living outside of Tsushima Island, hereafter referred to as Non-Tsushima Taishus (NTTs), are tagged. However, the genetic structure of the NTT individuals remains unclear, and such individuals are not included in the current mating plans for Taishu horses. Herein, we examined the genetic structure of 18 NTT individuals by comparing their genomic (SNP) information with that of individuals on Tsushima Island (TT), four other native Japanese breeds, and one Anglo-Arabian breed by using ddRAD-seq. We found that all individuals related to the Taishu can be grouped in one cluster, which was separated from other horse breeds. Patterns of specific and shared SNPs in NTT individuals closely resembled those of TT individuals, suggesting very minor genetic differences. Meanwhile, the heterozygosity of NTT individuals was slightly higher than that of TT individuals, and many NTT individuals were of fertile age, suggesting that the pedigree of NTT individuals would be useful in breed conservation plans for Taishu horses. Based on their genomic information, we also reconstructed the pedigree structures of four NTT individuals with no family information. The inclusion of NTT individuals in future mating plans on Tsushima Island may be an effective and feasible method for conserving the Taishu horse breed in Japan.

Local climatological study on layout of stone roof storehouses in Tsushima Island, Japan

Local climatological study on layout of stone roof storehouses in Tsushima Island, Japan

Comparisons of microhabitat use of Schlegel\u2019s Japanese gecko (Gekko japonicus) among three populations and four land cover types

BackgroundThe effective use of habitats is essential for the successful adaptation of a species to the local environment. Although habitats exhibit a hierarchical structure, including macro-, meso-, and microhabitats, the relationships among habitats of differing hierarchy have not been well studied. In this study, we studied the quantitative measures of microhabitat use of Gekko japonicus from three field populations in Japan: one at Tsushima Island, one at Nishi Park, Fukuoka, and one at Ohori Park, Fukuoka. We investigated whether land cover type, a higher hierarchical habitat component, was associated with quantitative microhabitat use, a lower hierarchical component, in these populations.ResultsThe substrate temperature where we located geckos (SubT) and the distance from the ground to the gecko (Height) were significantly different among the three populations. In particular, SubT on Tsushima Island was lower than it was in the other two populations. Irradiance at gecko location and Height were significantly different among the land cover types. In particular, Height in evergreen needleleaf forest was significantly lower than that in deciduous broadleaf forest. Furthermore, significant interactions between population and land cover type were observed for the SubT and Height variables.ConclusionsThe quantitative measures of microhabitat use of G. japonicus varied with population and land cover type, which exhibited significant interaction effects on microhabitat use variables. These results suggest that higher hierarchical habitat components can affect the quantitative measures of lower hierarchical microhabitat use in nocturnal geckos.

Taxonomic reconsideration of Chinese Lespedeza maximowiczii (Fabaceae) based on morphological and genetic features, and recommendation as the independent species L. pseudomaximowiczii

Lespedeza maximowiczii C. K. Schneid. (Fabaceae) is a deciduous shrub which is known to be distributed in the temperate forests of China, Korea and on Tsushima Island of Japan. Due to severe morphological variations within species, numerous examinations have been conducted for Korean L. maximowiczii. However, the morphology of Chinese plants has not been studied as thoroughly, despite doubts about their taxonomy. To clarify this taxonomic issue, we investigated morphological characters and undertook a Bayesian clustering analysis with microsatellite markers. The morphological and genetic traits of Chinese individuals varied considerably from those of typical L. maximowiczii growing in Korea. For example, petals of the former had a different shape and bore long claws, while the calyx lobes were diverged above the middle and the upper surface of the leaflet was pubescent. Their terete buds and spirally arranged bud scales were distinct from those within the series/section Heterolespedeza, which includes L. maximowiczii. Our Bayesian clustering analysis additionally included L. buergeri as an outgroup. Those results indicated that the Chinese samples clustered into a lineage separated from L. maximowiczii (optimum cluster, K = 2), despite the fact that the latter is grouped into the same lineage with L. buergeri. Therefore, we treat those Chinese plants as a new species with the name L. pseudomaximowiczii.