Recursos de colección
Hokkaido University Collection of Scholarly and Academic Papers (130.615 recursos)
今井, 一郎; 岡本, 悟; 西垣, 友和; 吉永, 郁生; 竹内, 照文
Seasonal fluctuations of algicidal bacteria were investigated with the microplate MPN method in surface seawater and on the surface of the green alga Ulva pertusa in cage culture for poly-culture at the stations in Shimo-Haya Bay, Wakayama Prefecture. Target red tide species were three raphidophytes of Chattonella antiqua, Heterosigma akashiwo and Fibrocapsa japonica, and two dinoflagellates of Karenia mikimotoi and Heterocapsa circularisquama. In seawater, most part of killer microorganisms was substantially algicidal bacteria, and the most abundant killer bacteria were killers for Karenia mikimotoi and followed by killers for Fibrocapsa japonica. The maximum value was 2.2×10^4 MPN ml^-1 for K. mikimotoi killers. On the surface...
板倉, 茂; 長崎, 慶三; 河村, 知彦; 今井, 一郎
In spite of its importance in microbiology, information on cryopreservation of marine diatom is limited. An attempt was made to develop cryopreservation procedure of marine diatom resting stage cells which abundantly exist in the bottom sediment of coastal area. Bottom sediment samples from the Seto Inland Sea (Harima-Nada) were used for sub-zero temperature preservation experiment in this study. The condition giving optimal survival of microalgae in cryopreserved sediments was as follows : with sorbitol (1 M) as additives, 1/3 salinity, at －80°C preservation (no pre-cooling). Under this condition, two diatoms, Thalassiosira pseudonana and Nitzschia sp., and some unidentified microalgae were recovered from the sediments,...
夏池, 真史; 金森, 誠; 馬場, 勝寿; 山口, 篤; 今井, 一郎
Chattonella globosa is known as a red tide species in western Japan from Kyushu, the Seto Inland Sea to Tokyo Bay, but the existence has been unknown in the northern Japan. This is the first report of the observation of occurrence of C. globosa from Funka Bay, in Hokkaido, Japan. Cells were globular and 33-42 μm in diameter with single flagellum, and sometimes performed “Amoeba-like movement”. We also studied the seasonal variation in density and distribution of C. globosa. This species was first detected in July 2011 and reached at maximum cell density of 2.6×10^4 cells L^-1 at the same time in the inner...
條野, 真奈美; 小林, 由美; 浅沼, 武敏; 坪田, 敏男; 桜井, 泰憲
In precocial species, fetuses often show adaptation to their particular environments. We investigated growth and morphology of 11 fetuses of Steller sea lion (Eumetopias jubatus), a highly precocial animal. The specimens were collected around Hokkaido, Japan in 2006-2008. Body length was found to increase gradually with gestational period, while body weight rapidly increased after the middle period (81-160 days) of gestation. Positive allometric growth indicating tachyauxesis was found only in the four limbs. This noteworthy limb development may indicate adaptation to postnatal movements on shore and in the water. The fur, which developed fully by birth, confirmed the importance of thermoregulation. MRI images suggested a progressive status...