By Chi Ling Wang
Dept. of Nature Science Education, National Chia-Yi Teacher's College, Taiwan
E. proxima
E. proxima
E. proxima
E. proxima
Pringsheim, Nova Acta Leopoldina 18: 62, fig. 8, 1956.Cells 46~86ƒÊm long, 12~25ƒÊm broad; moderately metabolic; fusiform or sometimes cylindrical, anterior end slightly narrowed and rounded, posterior end conically attenuated into a short, pointed hyaline cauda; pellicle spirally striated, 9~11 striae per 10ƒÊm; chloroplasts numerous, parietal, without pyrenoid, disk-shaped, 4~6ƒÊm in diameter; paramylon grains numerous, small oval to rod-shaped, scattered throughout the protoplasm; nucleus spherical, lying just behind the middle, 10~16ƒÊm in diameter; eyespot prominent, large, curved lamella-shaped with convex face outward, 4~7ƒÊm in length; locomotory flagellum, one to one and half body length, easily shedding; movement slowly swimming and rotating.
Occurrence in Chia-Yi: There were three local populations collected here, in three agricultural reservoir, Shui-Shang, FEB 1999; Hou-Pi, JUN 1999; Tai-Pao JUN 1999; respectively. It is recorded for the first time in Taiwan.
Taxonomic considerations: The most important features in identification of E. proxima are its spindle shape which with a short hyaline cauda, disk-shaped chloroplast without pyrenoid and numerous monomorphic paramylon grains (Kim et. al., 1998).
Notes: This alga is predominate in Summer in this local area. There were various metabolic forms had been observed, fusiform, cylindrical and non-motile ovoid cells.
The pellicular striation of cylindrical cell was nearly longitudinal and with double attenuation at posterior end.
Personal observations of this alga indicate that there were many cytoplasmic granules irregulary scattered beneath the pellicle which differed from that of E. variabilis.