【摘 要】
：
The species of Epithemia ocellata (Ehr.) Kütz. from Northeastern China were observed by scanning electron microscopy (SEM). The studies on silica valve formati
【机 构】
：
Department of Biology,Institute of Hydrobiology
【基金项目】
：
黑龙江省自然科学基金;国家自然科学基金;Project of Innovation Capacity of Teachers in University;Post-doctor Start-up Fund of the Heilongjiang Provincial Government
论文部分内容阅读
The species of Epithemia ocellata (Ehr.) Kütz. from Northeastern China were observed by scanning electron microscopy (SEM). The studies on silica valve formation in different stages were made.At the early stage, a Y-shaped raphe sternum was found. Areolae were made from virgae and vimines. In immature valves, the canal formation before the raphe fissure is visible. The raphe system, virgae and vimines (areolae) might be the early siliceous elements of the valve during morphogenesis. The formations of virgae and vimines are similar to that of Gephyria media W. Arnott. Rows of silica papillae formed gradually on the face of the valve. After the areolae were covered with silica and form rows of papillae, the outer valve surface could become mature. Details of the internal costae were observed in mature valves.
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