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Concept: Shikoku


A new echiuran, Arhynchite hayaoi sp. n., is described from newly collected specimens from sandy flats of the Seto Inland Sea, Japan, together with many museum specimens, including those once identified as Thalassema owstoni Ikeda, 1904 or Arhynchite arhynchite (Ikeda, 1924). The new species is clearly distinguishable from its congeners by the smooth margin of gonostomal lips and lack of rectal caecum. Brief references are also made to the morphological distinction between the new species and Thalassema owstoni, originally described from the deep bottom on the Japanese Pacific coast.

Concepts: Inland Sea, Pacific Ocean, Honshū, Annelid, Echiura, Shikoku, Sea of Japan, Japan


A new species of parasitic copepod, Choniomyzon inflatus n. sp., is described based on specimens collected from the external egg masses of the smooth fan lobster Ibacus novemdentatus Gibbes captured in the North Pacific Ocean off Ainan, Ehime Prefecture, western Japan. The new species differs from its congeners in having a globular to ovoid prosome, in bearing asymmetrically arranged denticles at a rounded apex of both the terminal segment of the antenna and the maxilliped, and in lacking serrate lobes on the basis of legs 1 and 2. The species is similar in size and shape to the host’s eggs, which may be interpreted as egg mimicry. The new species is the first member of Choniomyzon Pillai, 1962 from subtropical regions.

Concepts: Australia, Ehime Prefecture, Shikoku, Slipper lobster, New Zealand, Pacific Ocean, Crustacean, Japan


In the spring of 2012, a year after the Fukushima Daiichi nuclear disaster, radiocesium-contaminated Japanese cedar pollen may have caused internal exposure to the general population by inhalation. To determine if pollen had been contaminated through uptake of radiocesium by Japanese cedars and was therefore contributing to inhalation doses, the authors measured radiocesium and Japanese cedar pollen adhered to masks worn by 68 human subjects residing in eastern Japan, including Fukushima prefecture, for 8 wk in the spring of 2012. The maximum cumulative Cs and Cs radioactivities on masks worn by an individual were 21 ± 0.36 Bq and 15 ± 0.22 Bq, respectively, and the estimated effective dose during the 8 wk was 0.494 μSv. The average estimated effective dose during the 8 wk was 0.149 μSv in Fukushima prefecture and 0.015 μSv in other prefectures, including Tokyo metropolitan. The correlation between radiocesium activity and the Japanese cedar pollen count was moderate. However, imaging-plate and light microscopy observations showed that the main source of radiocesium adhered to masks was fugitive dust.

Concepts: Shikoku, Government of Japan, Fukushima Prefecture, Tōhoku region, Tokyo, Honshū, Prefectures of Japan, Japan


The red mite Balaustium murorum (Hermann) inhabits the Western Palaearctic realm and is well adapted to man-made structures. In Japan, B. murorum had been reported more frequently after the 1980s. A molecular phylogeny based on the nuclear 18S rRNA and mitochondrial COI genes, and including B. murorum individuals from Japan and Austria and representatives of related species from Japan showed four Balaustium species-level lineages in Japan (B. murorum, Balaustium sp. 1, Balaustium sp. 2, Balaustium sp. 3). The B. murorum lineage shared identical 18S sequence and COI haplotype with the Austrian population. Balaustium sp. 1 was detected from the Tokyo and Misaki area (Honshu Island) and was the sister group to B. murorum; the other two lineages inhabited coastal environments of Erimo, Hokkaido Island (Balaustium sp. 2) and Ainan, Shikoku Island (Balaustium sp. 3). The high genetic distances among these four lineages indicate that each lineage is a distinct species, with three of the lineages representing undescribed species. Our results are compatible with the conclusion that B. murorum was introduced to Japan from Europe, although our study did not resolve the polarity or timing of migration events.

Concepts: Japanese Archipelago, Hokkaidō, Tokyo, Japanese people, Shikoku, Honshū, Japan, Prefectures of Japan


We estimated the cost-effectiveness of direct acting antiviral treatment (DAA) compared to triple therapy (simeprevir, pegylated interferon-α and ribavirin) (scenario-1) and Peg-IFN+RBV(scenario-2) and non-antiviral therapy(scenario-3).

Concepts: Japan, Cancer, Shikoku, Hiroshima Prefecture, Prefectures of Japan, Honshū, Medicine


Furcohaptor brevis n. sp. is described from the gills of Cynoglossus robustus Günther caught in the Seto Inland Sea off Hiroshima Prefecture, Japan. Although Furcohaptor Bijukumar & Kearn, 1996 has been assigned to the Ancyrocephalinae Bychowsky, 1937 in the Dactylogyridae Bychowsky, 1933, this genus is transferred to the Diplectaninae Monticelli, 1903 in the Diplectanidae Monticelli, 1903 based on both morphological and molecular data. An amended generic diagnosis is provided.

Concepts: Prefectures of Japan, Itsukushima, Kure, Hiroshima, Sea of Japan, 1996, Japan, Shikoku, Honshū


Here, we report the draft genome sequence and annotation of Flavobacterium psychrophilum strain SSADA-1411. This strain was isolated from the skin ulcer of an ayu (Plecoglossus altivelis altivelis) migrating downriver to spawn in the lower Shimanto River, in western Kochi Prefecture on Shikoku Island in Japan.

Concepts: Ayu, Tokushima Prefecture, Honshū, Japan, Prefectures of Japan, Shikoku, Kōchi Prefecture


The Japanese archipelago stretches over 4000km from north to south and has four large islands: Hokkaido, Honshu, Shikoku, and Kyushu. Previously, using the Temperament Evaluation of Memphis, Pisa, Paris and San Diego-auto questionnaire version (TEMPS-A), we compared the hyperthymic scores of residents in Sapporo, Obihiro, Takaoka, Koshigaya, and Oita cities (which are located at latitudes of 43°N, 42°N, 36°N, 36°N and 33°N with various combinations of ambient temperament and sunshine in Japan, respectively). We found that latitude predicted significant variance in hyperthymic temperament, and that ambient temperature, but not sunshine, significantly affected hyperthymic temperament scores. However, the analysis failed to consider the effects of naturally occurring low-dose lithium on temperament.

Concepts: Islands of Japan, Shikoku, Japanese people, Prefectures of Japan, Japanese Archipelago, Honshū, Hokkaidō, Japan


In the World Health Organization (WHO)-coordinated Cardiovascular Disease and Alimentary Comparison Study, isoflavones (I; biomarker for dietary soy) and taurine (T; biomarker for dietary fish) in 24-hour-urine (24U) were inversely related to coronary heart disease (CHD) mortality. High levels of these biomarkers are found in Japanese people, whose CHD mortality is lowest among developed countries. We analyzed the association of these biomarkers with cardiovascular disease risk in the Japanese to know their health effects within one ethnic population. First, to compare the Japanese intake of I and T with international intakes, the ratios of 24UI and 24UT to creatinine from the WHO Study were divided into quintiles for analysis. The ratio for the Japanese was the highest in the highest quintiles for both I and T, reaching 88.1%, far higher than the average ratio for the Japanese (26.3%) in the total study population. Second, 553 inhabitants of Hyogo Prefecture, Japan, aged 30 to 79 years underwent 24-U collection and blood analyses. The 24UT and 24UI were divided into tertiles and adjusted for age and sex. The highest T tertile, compared with the lowest tertile, showed significantly higher levels of high-density lipoprotein-cholesterol (HDL-C), total cholesterol, 24U sodium (Na) and potassium (K). The highest I tertile showed significantly higher folate, 24UNa and 24UK compared with the lowest tertile. The highest tertile of both T and I showed significantly higher HDL-C, folate, and 24UNa and 24UK compared with the lowest tertile. Thus, greater consumption of fish and soy were significantly associated with higher HDL-C and folate levels, possibly a contributor to Japan having the lowest CHD mortality and longest life expectancy among developed countries. As these intakes were also associated with a high intake of salt, a low-salt intake of fish and soy should be recommended for healthy life expectancy.

Concepts: Death, Heart, Shikoku, Demography, World Health Organization, Honshū, Life expectancy, Japan


To study the effects of post-glacial isolation by islands on population genetic diversity and differentiation of the large Japanese field mouse, Apodemus speciosus, we examined partial nucleotide sequences of the mitochondrial Dloop region (ca. 300 bp) in 231 individuals collected from islands in the Seto Inland Sea and adjacent regions on Honshu and Shikoku Islands in the western part of the Japanese archipelago. Molecular phylogenetic and network analyses showed that haplotypes in each island tended to form monophyletic groups, while those in Honshu and Shikoku (the major Japanese islands) showed scattered relationships and were connected with island haplotypes. These observations suggest that a set of Honshu and Shikoku haplotypes became the ancestral lineages of the island population. No gene flow was detected among island populations, indicating that independent evolution occurred on each island, without the influence of human activities, since the establishment of the islands in the Holocene. Population genetic diversities on each island were lower than those on Honshu and Shikoku. Comparison between genetic diversity and island area size showed positive correlations and supported the suggestion that genetic drift is a major factor that shaped the current haplotype constitution of the islands in the Seto Inland Sea.

Concepts: Evolution, Island, Inland Sea, DNA, Shikoku, Honshū, Japan, Population genetics