Characteristic regional prevalence of HTLV-I in Shimane Prefecture

Serological survey for human T-lymphotropic virus type I (HTLV-I) was performed in Shimane Prefecture, Japan, located on the coast of Japan sea. The rates of anti-adult T-cell leukemia-associated antigen-positive sera were 4.2% and 6.9% respectively for males and females. The rate increased with age, particularly in females. From the geographical point of view, the Oki Islands and a very small focus in Shimane-cho had high rates of anti-adult T-cell leukemia-associated antigen positives. Even within the Oki Islands, there was a big difference in the rate of seropositives between Dozen and Dogo which are only 10 km apart. The focus, Shimane-cho, has a population of 299. Even within a small area, there is a tendency of HTLV-I carriers to form a very narrow focus.     

Relation between size and age of holdfasts of Ecklonia stolonifera Okamura (Laminariales,Phaeophyta) in northern Honshu,Japan

Ecklonia stolonifera is distributed along the coast facing the Sea of Japan. The size of various parts of the shoot (blade length and width and stipe length and diameter) and the age were determined at Ooma, Aomori Prefecture. The smaller the holdfast, the higher the percentage of one-year-old shoots. Holdfasts 10 cm in diameter seemed to be three years old, whereas holdfasts 40 cm in diameter seemed to be five or more years old. Zoosporangial sori were observed on blades three or more years old. Ecklonia stolonifera holdfast diameter expands only vegetatively by stoloniferous rhizoids. Zoospores, formed on shoots three or more years old, serve for the formation of new populations.     

Apterichtus keramanus, a new snake-eel from Okinawa, southern Japan (Ophichthinae, Ophichthidae)

A new snake-eel,Apterichtus keramanus, is described on the basis of a single 276-mm TL specimen trawled from the coast of Kerama Islands, Okinawa Prefecture, Japan. The species is unique in the genus in having the posterior nostril opening entirely inside the mouth and a dark band running from the anteroventral margin of the eye to the upper lip.     

Erythroglossum latum sp. nov. (Delesseriaceae, Rhodophyta) from the east coast of Honshu, Japan

A new species, Erythroglossum latum, is described based on specimens from Fukushima Prefecture along the east coast of Honshu, Japan. This species differs from Erythroglossum pinnatum Okamura in having a broader main blade, a clear midrib and lateral branches that are smaller in size and not clearly constricted at the base.     

Chemical composition of Laurencia spp. collected from the Seto Inland Sea of Japan

The chemical composition of three Laurencia spp., Laurencia sp., L. okamurae and L. saitoi, which were collected from the Seto Inland Sea of Japan, has been examined. Laurencia sp. collected from the coast of Matoba Park, Takehara, Hiroshima Prefecture, contained a brominated chamigrane-type sesquiterpene (1), named matobol, as the main metabolite. The structure of matobol was determined as (+)-(2R,3R,6R,10S)-2,10-dibromochamigr-7(14)-en-3-ol (1). This is the first time that the optically active 1 has been isolated from Laurencia. On the other hand, L. okamurae from the coast of Ikunoshima Island, Hiroshima Prefecture, produced laurinterol (2) that is a known cyclolaurane-type sesquiterpene characteristic to this species in Japan. L. saitoi from the coast of Matoba Park contained a known bromoallenic C₁₅-acetogenin, neolaurallene (3).     

Molecular survey of Babesia microti, Ehrlichia species and Candidatus neoehrlichia mikurensis in wild rodents from Shimane Prefecture, Japan

A significant number of patients are diagnosed with "fevers of unknown origin" (FUO) in Shimane Prefecture in Japan where tick-borne diseases are endemic. We conducted molecular surveys for Babesia microti, Ehrlichia species, and Candidatus Neoehrlichia mikurensis in 62 FUO cases and 62 wild rodents from Shimane Prefecture, Japan. PCR using primers specific for the Babesia 18S small-subunit rRNA (rDNA) gene and Anaplasmataceae groESL amplified products from 45% (28/62) and 25.8% (16/62) of captured mice, respectively. Of the 28 18S rDNA PCR positives, 23 and five samples were positive for Hobetsu- and Kobe-type B. microti, respectively. In contrast, of the 16 groESL PCR positives, eight, one and seven samples were positive for Ehrlichia muris, Ehrlichia sp. HF565 and Candidatus N. mikurensis, respectively. Inoculation of selected blood samples into Golden Syrian hamsters indicated the presence of Hobetsu- and Kobe-type B. microti in four and one sample, respectively. Isolation of the latter strain was considered important as previous studies suggested that the distribution of this type was so far confined to Awaji Island in Hyogo Prefecture, where the first case of transfusion-associated human babesiosis originated. DNA samples from 62 FUO human cases tested negative for B. microti 18S rDNA gene, Anaplasmataceae groESL gene, Rickettsia japonica 17K genus-common antigen gene and Orientia tsutsugamushi 56K antigen gene by PCRs. We also conducted seroepidemiological surveys on 62 human sera collected in Shimane Prefecture from the FUO patients who were suspected of carrying tick-borne diseases. However, indirect immunofluorescent antibody tests using B. microti- and E. muris-infected cells detected IgG against E. muris in only a single positive sample. This study demonstrates the presence of several potentially important tick-borne pathogens in Shimane Prefecture and suggests the need for further study on the causative agents of FUOs.     

Evidence for infection caused by spotted fever group Rickettsia in Kyushu, Japan

Of 50 cases that gave negative immunofluorescence reaction with Rickettsia tsutsugamushi among patients with suspected tsutsugamushi disease encountered in Miyazaki Prefecture during the last four years, three showed a significant rise in the antibody titer to Rickettsia montana, a species of spotted fever group. This paper reports evidence for the occurrence of the rickettsial infection of the spotted fever group in Kyushu, Japan.     

Population structure of the sailfin sandfish, Arctoscopus japonicus (Trichodontidae), in the Sea of Japan

We analyzed patterns of genetic diversity in the sailfin sandfish (Arctoscopus japonicus), focusing on population subdivisions within the Sea of Japan. We observed 270 specimens from nine sampling sites in 1999–2000, i.e., seven sites in the Sea of Japan and two sites from the Pacific coast of Hokkaido. An additional site (30 specimens) was sampled from eastern Korea in the spawning season of 2004 for comparison. Forty haplotypes, compiled into three haplogroups (A–C), were detected based on the comparison of a 400-bp sequence of the anterior part of the mitochondrial control region. In accordance with previous hypotheses from morphological and molecular analyses, genetic discontinuity between the Sea of Japan and the Pacific coast of Hokkaido was conspicuous. Within the Sea of Japan, eight sampling sites were not genetically uniform, and most of the variations among sites were detected between eastern Korea [the “eastern Korea” (EK) population: distributed from the Korean Peninsula to Mishima, Yamaguchi Prefecture] and the other sites along the coast of Japan [the “western Japan” (WJ) population: from Oki Islands to western Hokkaido] (Φ _CT  = 0.096, P = 0.0183). The WJ population, having lower genetic variability, showed significant departure from neutrality, indicating influences through a recent population expansion. The period of the expansion can be estimated to have begun on the order of 10⁴ years ago. We consider that the present Japan Sea populations have been formed through the invasion of a small ancestral stock to the Sea of Japan and its population expansion during the last glacial period or later. On the other hand, we failed to detect distinct evidence of a population expansion in the EK population. Haplogroup C, detected in a high frequency in this population, was estimated to have mixed with haplogroup A after rapid differentiations of the latter. Therefore, the EK population, strongly influenced by such a mixture, might possess haplogroup C in a higher frequency and a different haplotype composition from the WJ population.     

Ecological impacts of the 2011 Tohoku Earthquake Tsunami on aquatic animals in rice paddies

The 2011 Tohoku Earthquake Tsunami hit the Pacific coast of eastern Japan on March 11, 2011 and disturbed various ecosystems, including rice paddies along the coast. In Miyagi Prefecture, located in the Tohoku Region, a total of 12685 ha, or about 11.5 % of the rice paddies, were inundated and damaged by the tsunami. Although rice paddies are artificially constructed, they have long been used by many kinds of aquatic animals as habitats. To assess impacts of the 2011 Tohoku Earthquake Tsunami on aquatic animals inhabiting the rice paddies, census surveys were conducted at inundated and non-inundated rice paddies at six sites along the coast of Miyagi Prefecture from June to July 2012. This was 30–60 days after the first transplanting of rice seedling in inundated rice paddies following the tsunami. In the surveys a total of 100 aquatic animal taxa, 72 from inundated and 86 from non-inundated rice paddies, were found. Although the taxonomic richness and composition differed among the sites, the total number of observations of walk dispersers and obligatory aquatic animals without resting stages were significantly lower in inundated than in non-inundated rice paddies. However, no notable difference was detected in taxonomic richness and the total number of observations of flight dispersers and obligatory aquatic animals with resting stages between inundated and non-inundated rice paddies. The results showed that the tsunami had a substantial impact on freshwater animals but that restoration of the paddies for rice cultivation enhanced rapid recolonization by aquatic animals with high dispersal abilities and resting stages.     

History of Katayama disease: schistosomiasis japonica in Katayama district, Hiroshima, Japan

Historical account of Katayama disease is presented as a centenary record since the discovery of Schistosoma japonicum in Japan in 1904. The ever unknown endemic disease was called Katayama disease. Katayama district, Hiroshima Prefecture is one of endemic areas of schistosomiasis japonica in Japan. The causative parasite was first discovered in a human case in Katayama district. After the discovery of the parasite, life history, diagnosis, treatment, control measures and even eradication have been worked out, attempted and succeeded in Katayama district together with other endemic areas in Japan. Hiroshima Prefecture declared safety from the disease in 1980.     

Population genetic structure of Potamogeton anguillanus in Lake Shinji, Japan

Enzyme electrophoresis was performed to investigate the genetic variation of Potamogeton anguillanus Koidz. in Lake Shinji, Shimane Prefecture, Japan. The collection was made in six local populations along the coast of the lake, and a total of 78 shoot samples were obtained. No variation among samples occurred in the six enzymes analyzed, and the whole population in Lake Shinji was proved to consist of only a single multienzyme phenotype. Clonal growth without sexual reproduction may have resulted in the genetic uniformity. The implication of the lack of genetic variation is briefly discussed from the viewpoint of conservation of the species in Lake Shinji. Received: July 11, 2000 / Accepted: October 5, 2000     

Asexual life history by biflagellate zoids in Monostroma latissimum (Ulotrichales)

Monostroma latissimum (Kuetzing) Wittrock is a monostromatic green alga of commercial importance in Japan. Here we report the serendipitous discovery of asexually reproducing specimens collected from Usa, on the Pacific coast of Kochi Prefecture, south-western Japan. Zoids were found to be biflagellate and negatively phototactic. Germination of settled zoids was observed to follow erect-filamentous ontogeny similar to that of the previously reported sexual strain. Moreover, the newly discovered asexual strain had identical sequences of nuclear encoded ITS (Internal Transcribed Spacer) region to that of the sexual strain. On the basis of this finding, we postulate that the ITS sequences may have been maintained in these conspecific strains despite the evolution in sexuality. Relationships were investigated among M. latissimum and other monostromatic taxa within the class Ulvophyceae using ITS sequences in order to understand relative phylogenetic position of this species.     

Sorellocolax stellaris gen. et sp. nov., a hemiparasitic alga (Delesseriaceae, Rhodophyta) from the east coast of Honshu, Japan

A hemiparasitic alga, Sorellocotax stellaris sp. nov. is described growing on plants of Sorella repens collected from Onagawa, Miyagi Prefecture, east coast of Honshu, Japan. The thallus is small, up to 2 mm high, once or twice branched from the margin. The growing apex has a transversely dividing apical cell, and intercalary cell divisions occur in the cells of first-order rows. Tetrasporangia are cut off from the cells of the inner cortex, The procarp is composed of a supporting cell, one group of sterile cells and two carpogonial branches. Carposporangia are borne in short chains.     

Taxonomic review of East Asian <Emphasis Type="Italic">Pleuronichthys</Emphasis> (Pleuronectiformes: Pleuronectidae), with description of a new species

A review of East Asian frog flounders, genus Pleuronichthys (family Pleuronectidae), recognized Pleuronichthys japonicus sp. nov. and P. cornutus (Temminck and Schlegel 1846). Pleuronichthys japonicus sp. nov. is characterized by small, dark, rounded spots or marbled markings on the ocular side of the body, rounded cycloid scales somewhat irregularly arranged, usually 12 abdominal vertebrae, 67–80 (modally 75) dorsal-fin rays, 48–59 (modally 55) anal-fin rays, and a short branch of the supratemporal lateral line usually present on both sides. Pleuronichthys cornutus is characterized by densely distributed small, dark, irregular spots on the ocular side of the body, elongate cycloid scales somewhat regularly arranged, usually 13 abdominal vertebrae, 72–88 (modally 77) dorsal-fin rays, 52–65 (modally 58) anal-fin rays, and a branch of the supratemporal lateral line usually absent on both sides. Whereas P. cornutus is distributed from Miyagi Prefecture (Tohoku District) southward along the Pacific coast of Japan to the Bungo Channel, from Akita Prefecture (Tohoku District) southward along the Sea of Japan coast through the Tsushima Strait to the East China Sea, Yellow and Bohai Seas, the Taiwan Strait, and northern Chinese coast of the South China Sea, P. japonicus is distributed from southern Hokkaido southward along the Sea of Japan and Pacific coasts of Japan to the southern East China Sea. Geographic variations were found in caudal vertebrae and anal-fin ray counts, and caudal-peduncle depth in P. cornutus, and in ocular side body coloration, body depth, and head length in P. japonicus. Pleuronichthys lighti Wu 1929 was regarded as a junior synonym of P. cornutus.     

846. TRICYRTIS MACRANTHA

Tricyrtis macrantha Maxim. (Liliaceae), an endemic species to Japan, is illustrated. It is distributed in a small area in Shikoku (Kochi Prefecture), and grows on limestone cliffs. Tricyrtis macrantha and its allied species, T. macranthopsis Masam., distributed in Kii Peninsula in western Honshu, and T. ishiiana (Kitag. & T. Koyama) Ohwi & Okuyama, distributed in Pacific coast side of central Honshu, comprise one natural group.     

A new threespine stickleback,Gasterosteus nipponicus sp. nov. (Teleostei: Gasterosteidae), from the Japan Sea region

Gasterosteus nipponicus sp. nov. is described from the holotype, 35 paratypes, and 60 additional specimens. The species differs from congeners in the following combination of characters: lateral plates complete, abruptly reducing in size above the anus, depth of lateral plate above the anus < 60 % that of the deepest plate; caudal keels thin, membranous. The new species is distributed in coastal Japan facing the Sea of Japan from Kyushu to Hokkaido Islands, along the Pacific coast of northern Japan from the Chiba Prefecture to Hokkaido, along the Sea of Okhotsk of Hokkaido, west to the southern and eastern coasts of Korean Peninsula, the Maritime Territory and north to Sakhalin Island, Russia.     

Seroepizootiological survey on bluetongue virus infection in cattle in Japan

Bovine sera collected in various parts of Japan were subjected to seroepizootiological tests with bluetongue virus type 1 (BTV1), type 12 (BTV12), and type 20 (BTV20). All these viruses have been widely disseminated among cattle in the southern part of Japan in 1974. Relatively high incidences of neutralizing (NT) antibody against the three viruses were shown among cattle in the Kyushu district, including Okinawa Prefecture, or the southern part of Japan, but extremely low or incidences in Hokkaido, or the northern part of Japan. The incidence of reactors was higher in old animals. Cattle in Okinawa Prefecture showed a high rate of seroconversion for all the viruses during the summer of 1979. None of the animals seroconverted, however, manifested any sign of disease. Seroepizootiological investigation made it clear that BTV1, BTV12 and BTV20 had existed in Japan and that the epizootic of bluetongue virus infection started during a period from summer through early autumn.     

Zoonotic filariasis caused by Onchocerca dewittei japonica in a resident of Hiroshima Prefecture,Honshu, Japan

A female of Onchocerca sp. was found to be the probable causative agent of a subcutaneous nodule in the left knee of a 70-year-old man in a rural area of Hiroshima Prefecture, Honshu, the main island of Japan. We compared the characteristics of the agent with the features of the four previously suspected species found in cattle and horses in various parts of the world, as well as O. lupi and O. jakutensis that were suspected or proved, respectively, in zoonotic cases in Europe. In addition, the morphologic characteristics of this parasite were compared with those of the four Onchocerca species found in wild animals in Japan. Based on such characteristics as the large triangle ridges, the considerable distance between any two adjacent ridges, and the absence of inner cuticular striae in the longitudinal sections, we found the causative agent in the present case to be identical to the female of Onchocerca dewittei japonica. All five previous cases of zoonotic onchocerciasis in Japan had been found in Oita, Kyushu, the main southern island. This human case caused by O. dewittei japonica suggests that zoonotic onchocerciasis is liable to occur in rural areas in Japan where wild boar, Simulium vectors, and humans overlap.