Diatoms from Ishite Stream, near the Komenono Forest Research Center of Ehime University, Japan

Abstract

Diatoms from Ishite Stream near the Komenono Forest Research Center of Ehime University in Matsuyama, Ehime Prefecture, Japan, were studied. Samples were collected from the surface of pebbles and a cobble on 14 November 2003 and 22 November 2005. Based on light microscopy of cleaned diatom frustules, we identified a total of 99 diatom taxa belonging to 39 genera. A checklist including nine unidentified taxa is provided herein, along with light micrographs. Achnanthes minutissima var. robusta Hust. is raised to species level with its transfer to the genus Achnanthidium, i. e., as Achnanthidium robustum (Hust. ) Ohtsuka comb. nov. et stat. nov. Synedra ramesi Hérib. is transferred to a morphologically more suitable genus, as Ulnaria ramesi (Hérib. ) Ohtsuka comb. nov. Many taxa that have never or rarely been reported from Japanese rivers are noted here. A review of light micrographs in past literature, however, reveals that most of these taxa have in fact been known to occur in Japanese rivers, but have been either unidentified or identified as other taxa heretofore.