Abstract
The River Amano (Amano-gawa), located in the eastern side of Lake Biwa, is about 20 km in its total length along the axis. It takes its source from two limestone-mountains, Ryozen (1084 m above the sea) and Ibuki (1377m above the sea), and flows into Lake Biwa. Its water is rich in lime (Ca 30-43mg/1), alkaline (pH 8.1-8.4), and has the pretty high electric conductivity (180-254 μs/cm) .
The diatom flora of the River Amano is composed of 54 forms belonging to 20 genera and the diatom communities at five selected stations of the river are as mentioned below;
St. 1Diatoms vulgarevar.products-Cymbella turgidulavar, nipponica-Gomphonema quadripuctatum-Association
St.2*Cyclotella socialis-Fragilaria construens var, binodis-Cymbella leptoceros-Association
St.3Diatoms vutgarevar.products-Navicula capitatoradiata-Cocconeis placentula var. euglypta-Association
St.4Navicula capitatoradiata-Cymbella turgidula var. nipponica-Diatoma vulgare var. producta-Association
St. 5Cocconeis placentula var.euglypta-Nitzschia pales-Diatoms vulgare var. products- Association
(*Station 2 is a spring and its flow near the proper cource of the river)
