Studies on the Thermal Algae of Hokkaido(1)

Abstract

The Hot Spring of Bankei is situated on the left bank in the upper part of the river Tyoryu, which flows into Hunka Bay. The water of the spring is meager in dissolved substances. The temperature of hot water near the vent is at about 70℃, while the known range of algal growth lies at temperatures between 25℃ and 53℃. The tubes of sample algae were collected by the writer on August 2, 1938. The vegetation of this spring consists of seventeen menbers of algae. Chynophyceae: (1) Chroococcus turgidus (KUTZ.) NAG. Small specimens, diam. of protoplasm 10-15μ, cum integ. 14-21μ. Temp. 38.9℃. (2) Chr. turgidus var. thermalis (KUTZ.) RABH. Diam. of protoplasm 6-6.5μ. Temp. 38.9℃. (3) Synechococcus elongatus var. amphigranulatus COPELAND. Crass. cell. 2-2.5μ; long, cell. 6-10μ. Temp. 50-53℃.(4)Mastigocladus laminosus COHN. One of the most dominant algae of the vegatation. Temp. 51-53℃. (5) Oscillatoria princeps VAUCH. var. tenella COPELAND. Crass. trich. 15-22μ; cells 1/8-1/4 time longer than their diameter. Temp. 25-38.9℃, pH 6.2-6.5. Forming deep blue-green strata in standing or slowly flowing warm water. Specimens of coiled filament are occasionally found in the sample of no. 7. (6) Oscillatoria anguina (BORY) GOM. Crass. trich. 6μ; cells 1/4-1/3 time longer than their diameter. Temp. 38.9℃. Rare. (7) Oscillatoria tenuis AG. Crass. trich. 6-8μ; cells about 1/3 time longer than their diameter. Temp. 25-38.9℃. They occur scattered among other Cyanophyceae. (8) Oscillatoria geminata MENEGH. Crass. trich. 2.5-3μ; long. cell. 3-9μ. On the bottom or on rocks in standing hot water, temp. 53℃. (9) Oscillatoria formosa BORY. Crass. trich. 4-5μ; long. cell. 2-4μ; not granulated at the cross walls. In slowly flowing warm water, mixed with O. princeps var. tenella, temp. 32℃. (10) Spirulina subtilissima KUTZ. Crass. trich. 0.5-4μ. Scattered among other Cyanophycean algae, temp. 32℃. (11) Phorimidium laminosum (AG.) GOM. Crass. trich. 1-2μ; long. cell. 3-6μ. Forming tufts in the flowing hot water or floating on the surface of standing water, temp. 50-53℃, pH 5.9-6.2.