도시하천의 환경요인과 Euglena viridis 의 형태 변이 및 밀도와의 관계

The morphological variation and density of the Euglena viridis cells and environmental factors of urban waterways of Daejoncheon, Jeonjucheon, Kwangjucheon, Kurnhogang, Mihocheon, and Musimcheon, Korea were studied from 25 December, 1995 to 5 January, 1997 in order to elucidate possible relationships among the biological and abiological factors. All E. viridis cells were same in having single star-cluster of chloroplast lobes and included two morphotypes based on other detailed morphology. The morphotype I cells agreed well with the typical form of E. viridis and commonly occurred in most of waters and bloomed with 5,386 cells ㆍ mL^(-1) in Kwangjucheon. The density of the morphotype I positively correlated with ammonium (r = 0.80) and nitrite (r = 0.68), while negatively with nitrate concentration. The morphotype II cells were characterized by having randomly scattered cytoplasmic granules beneath pellicle and unevenmargined lobes of chloroplasts. The density of the morphotype II positively correlated with nitrate (r = 0.98), while negatively correlated with ammonium and nitrite. However, the density of each morphotype was not significantly related with inorganic phosphate, temperature and pH of surface water. These results indicate that E. viridis includes two morphotypes in urban waterways in Korea, that coexist in the same period and station as a response of allocation of nitrogenous nutrients.