Abstract

During an extensive survey of Cymbella diatoms in freshwater bodies in South Korea, seven species that had not been previously reported in this country were documented. The two species recently reported as new to science in China, C. compactiformis B. Liu & Williams and C. distalebiseriata B. Liu & Williams, have been confirmed to exist in the Korean fresh water. The existence of two subspecies, Cymbella neoleptoceros var. tenuistriata Krammer and C. tropica var. tenuipunctata Krammer is known; most C. neoleptoceros Krammer assemblages observed here are mainly the variety, while in the case of C. tropica Krammer, most are the nominate variety and the variety is rare. In addition, the two diatom species, C. maggiana Krammer and C. subcistula Krammer, were identified in this region. Taxonomically redefined Cymbella excisa Kützing was observed at considerable frequency in the local area. Among these, three taxa, Cymbella compactiformis, C. neoleptoceros var. tenuistriata and C. subcistula, have large variations in the size of valves and also large variability in the valve morphology within each assemblage.