タンチョウの寄生蠕虫類調査

A helminthological survey was performed on 75 individuals of Tancho, Grus japonensis, from Hokkaido, Japan. A total of seven helminth species, including five nematode (Baruscapillaira sp., Contracaecum sp., Paracuaria adunca, Syncuaria sp., Viktorocara sp.) and two trematode (Echinostoma gotoi, Apatemon gracilis) species were obtained from 57.3% of the cranes, and E. gotoi was the most common encountered. Among the above helminths, all helminths except for E. gotoi were the first host records for G. japonensis worldwide, and Syncuaria sp. was the first geographical record from Japan. Since the acuariid nematodes including the genera Paracuaria, Syncuaria and Viktorocara are known to cause ulcerative ventriculitis and/or enteritis in bird alimentary tracts, monitoring of helminths is recommended in this endangered crane species. 2000年から2009年の間に北海道内各地で傷病個体として回収された後、斃死したタンチョウ75個体の寄生蠕虫類保有状況を調査した。57.3%から線虫5種(Baruscapillaira sp., Contracaecum sp., Paracuaria adunca, Syncuaria sp., Viktorocara sp.)および吸虫2種(Echinostoma gotoi, Apatemon gracilis)の計7種の蠕虫類のいずれかが検出された。E. gotoiを除く6種はタンチョウから初記録であり,Syncuaria sp.は日本初記録であった。得られた蠕虫類の中にはParacuada属, Syncuaria属およびViktorocara属など,消化管潰瘍や腸炎の原因となる線虫が含まれたため,絶滅危惧種であるタンチョウの保護管理上,今後寄生虫のモニタリングが必要であると考えられた

Vertebral Formula in Red-Crowned Crane (Grus japonensis) and Hooded Crane (Grus monacha)

Red-crowned cranes (Grus japonensis) are distributed separately in the east Eurasian Continent (continental population) and in Hokkaido, Japan (island population). The island population is sedentary in eastern Hokkaido and has increased from a very small number of cranes to over 1,300, thus giving rise to the problem of poor genetic diversity. While, Hooded cranes (Grus monacha), which migrate from the east Eurasian Continent and winter mainly in Izumi, Kagoshima Prefecture, Japan, are about eight-time larger than the island population of Red-crowned cranes. We collected whole bodies of these two species, found dead or moribund in eastern Hokkaido and in Izumi, and observed skeletons with focus on vertebral formula. Numbers of cervical vertebrae (Cs), thoracic vertebrae (Ts), vertebrae composing the synsacrum (Sa) and free coccygeal vertebrae (free Cos) in 22 Red-crowned cranes were 17 or 18, 9-11, 13 or 14 and 7 or 8, respectively. Total number of vertebrae was 47, 48 or 49, and the vertebral formula was divided into three types including 9 sub-types. Numbers of Cs, Ts, vertebrae composing the Sa and free Cos in 25 Hooded cranes were 17 or 18, 9 or 10, 12-14 and 6-8, respectively. Total number of vertebrae was 46, 47, 48 or 49, and the vertebral formula was divided into four types including 14 sub-types. Our findings clearly showed various numerical vertebral patterns in both crane species; however, these variations in the vertebral formula may be unrelated to the genetic diversity