Epilithic diatoms of Sendai River, Tottori Prefecture, Japan

Abstract

A study was conducted on the diatom flora and its distribution along the Sendai River, which flows into the Japan Sea in Tottori Prefecture in western Honshu, Japan. Diatoms were collected from cobbles near the riverside at each of 26 sampling sites in July-August 2006. A total of 165 diatom species belonging to 55 genera were identified and illustrated together with 10 unidentified ones. The predominant genera were Navicula and Nitzschia, represented by 21 and 17 species and by relative frequencies of 17% and 21%, respectively. The DAIpo value for each site was between 64 and 89, indicating that all sites were oligosaprobic. Distribution of Gomphonema parvulum inclined toward the upper part of the Sendai River, as found in some other rivers flowing into the Japan Sea in western Honshu.