岐阜県下諸温泉の細菌類及び藻類

抄録

Gihu Prefecture consists of the two provinces, Mino and Hida. In Mino there are only cold inineral springs, but in the mountainous region of Hida there are several hot springs-Hodaka, Yarimi, kamada, Hukuzi, Hira-yu and Nigogrigawa. These hot springs are mostly at altitudes of 1000 meters or so ; among them Nigorigawa (or Takeno-yu) is about 1780 meters above the sea level in Mt. Ontake. The majority of the materials forming the present subject were mostly collected from these hot springs by the writer in October 1941. The research shows 83 microorganisms in all, , including 3 Bacteria, 43 Cyanophyceae, 5 Chlorophyceae, 10 Conjugales and 22 Bacillariophyceae. the systematic list and the thermal distribution of these plants are given in the preceeding pages. the occurrence of Cyanophyceae was most frequently observed. Lyngbyas showed only small development at the hot spring of Nigorigawa. the frequent occurrence of Desmids and Diatoms is noticeable, but most of them are essentially non-thermal origin, invading only into tepid water. Some diatoms - Synedra ulna, Achnanthes exigua, Pinnuliria appendiculata, P. viridis, Nitzschia thermalis, N. palea- are considered as thermophilous. the important and typical thermal representatives in this investigation were Synechococcus elongatus v. amphigranulatus, Mastigocladus laminosus, Oscillatoria formosa and Phormidium laminosnm. the total temperature range of thermal vegetation was from 26℃ to 72℃. bacteria were found only at one site in the hot water of temperature 54℃ (at Hira-yu). For Cyanophyceae the upper temperature limit was 72℃ at Hira-yu, where growing Synechococcus elongatus v. amphigranulatus and Oscillatoria geminata. For Chlorophyceae and Conjugales the limit was 40℃ (at Hodaka), where Oedogonium sp. and Cosmarium subcrenatum were growing. For Bacillariophyceae the limit was 56℃ (at Hira-yu), where Pinnularia appendiculata was growing. the total range of pH was from 6.3 to 8.0. Any characteristic relation concerning the value of pH and thermal algal distribution was not evident in this study. The following plants are newly added to the Japanese thermal flora. Cyanophyceae : Synechococcus Vulcanus v. bacillarioides, Oscillatoria ornata, O. Jovis, O. homogenea. Chlorophyceae : Cladophora sp. Conjugales : Cosmarium Meneghinii, C. subcrenatum, Staurastrum punctulatum. Bacillariophyceae : Eunotia pectinalis v. minor, Navicula laterostrata, N. lanceolata, Pinnularia microstauron v. Brebissonii, P. nodosa, Gomphonema parvulum, Nitzschia obtusa. Besides these, Oscillatoria subspiroides is described as new to science.