Time filter

Source Type

Rishiri Town, Japan

Kawai K.,Hokkaido University | Kawai K.,Smithsonian Institution | Fukui D.,Japan Forestry and Forest Products Research Institute | Sato M.,Rishiri Town Museum | And 2 more authors.
Acta Chiropterologica

In December 2005, three bats of indeterminate identity were captured in northern Japan. Their forearm lengths were slightly smaller than the average for Vespertilio sinensis. We identified these three individuals as V. murinus using both morphological and molecular approaches, and discussed their possible migration or vagrancy routes. Prior to the first record of V. murinus on Rebun Island near Hokkaido in 2002, there was no record of this species in Japan. These new occurrences illustrate the importance of determining possible migration or vagrancy routes of bats for understanding and preventing the spread of zoonotic diseases. © Museum and Institute of Zoology PAS. Source

Hosokawa T.,Japan National Institute of Advanced Industrial Science and Technology | Nikoh N.,Chiba University | Koga R.,Japan National Institute of Advanced Industrial Science and Technology | Sato M.,Rishiri Town Museum | And 3 more authors.
ISME Journal

Bat flies of the family Nycteribiidae are known for their extreme morphological and physiological traits specialized for ectoparasitic blood-feeding lifestyle on bats, including lack of wings, reduced head and eyes, adenotrophic viviparity with a highly developed uterus and milk glands, as well as association with endosymbiotic bacteria. We investigated Japanese nycteribiid bat flies representing 4 genera, 8 species and 27 populations for their bacterial endosymbionts. From all the nycteribiid species examined, a distinct clade of gammaproteobacteria was consistently detected, which was allied to endosymbionts of other insects such as Riesia spp. of primate lice and Arsenophonus spp. of diverse insects. In adult insects, the endosymbiont was localized in specific bacteriocytes in the abdomen, suggesting an intimate host-symbiont association. In adult females, the endosymbiont was also found in the cavity of milk gland tubules, which suggests uterine vertical transmission of the endosymbiont to larvae through milk gland secretion. In adult females of Penicillidia jenynsii, we discovered a previously unknown type of symbiotic organ in the Nycteribiidae: a pair of large bacteriomes located inside the swellings on the fifth abdominal ventral plate. The endosymbiont genes consistently exhibited adenine/thymine biased nucleotide compositions and accelerated rates of molecular evolution. The endosymbiont genome was estimated to be highly reduced, ∼0.76 Mb in size. The endosymbiont phylogeny perfectly mirrored the host insect phylogeny, indicating strict vertical transmission and host-symbiont co-speciation in the evolutionary course of the Nycteribiidae. The designation Candidatus Aschnera chinzeii is proposed for the endosymbiont clade. © 2012 International Society for Microbial Ecology All rights reserved. Source

Yamauchi T.,Toyama Institute of Health | Sato M.,Rishiri Town Museum | Ito T.,Hokkaido Institute of Public Health | Fujita H.,Mahara Institute of Medical Acarology | And 5 more authors.
International Journal of Acarology

Tick fauna and tick-borne pathogenic bacteria were surveyed on Rishiri Island, off the northwest coast of Hokkaido, Japan. We collected Ixodes pavlovskyi and Ixodes persulcatus from vegetation, Ixodes angustus from Myodes rex, and Ixodes tanuki from Mustela itatsi and Felis silvestris catus. Borrelia garinii, the cause of Lyme disease in Eurasia, and Rickettsia helvetica and Rickettsia tarasevichiae of the spotted fever group were detected from I. persulcatus. These results indicate a potential threat of Lyme disease and spotted fever group rickettsiosis on Rishiri Island. It is possible that an introduced species, Mu. itatsi, contributes to maintenance of the infectious diseases as a blood source for the ticks on the island. © 2013 Taylor & Francis. Source

Kazama K.,Meijo University | Sato M.,Rishiri Town Museum | Kosugi K.,Northern Hokkaido branch of Wild Bird Society of Japan
Ornithological Science

Breeding population abundance such as colony size of seabirds is not generally considered to be particularly sensitive to the annual dynamics of the food conditions because of the long life-span and high adult survival rate. However, in seabird species in which adults decide to breed or not depending on the food conditions, population abundance can respond sensitively to the annual variation in the food conditions. Here, we examine the effects of the regional annual stock abundance of Japanese Sand Lance Ammodytes personatus, and their local temporal availability during the egg-laying period on the size of a Black-tailed Gull Larus crassirostris and Slatybacked Gull L. schistisagus, breeding colony over 12 years on Rishiri Island, northern Japan. The total number of nests of both gull species increased significantly with the regional annual stock abundance, but not with the local temporal availability of the sand lance. The number of Black-tailed Gull nests without eggs was significantly higher in the year with lower local temporal availability indicating that more Black-tailed Gull parents gave up egg-laying after nest building. Colony size in these species can be a useful indicator reflecting local food conditions. © The Ornithological Society of Japan 2016. Source

Discover hidden collaborations