Systematic Investigation of the Diatom Genus Tabellaria

硅藻，单细胞藻类，细胞壁富含二氧化硅， 是重要的生态指标 水质和营养状况， 适应特定的条件。 将其用作指标 依赖于物种的可靠分类，使用 细胞壁的稳定形态特征。 硅藻细胞 墙壁很容易保存为化石，例如在湖床 核心，并使分析非常长期的变化成为可能 在物种组成和丰富度方面， 可靠的分类标记。 尤金·斯托默博士 密歇根大学正在研究 Tabellaria属，以评估形态学的限制 这一组物种内部和之间的变异。 Tabellaria物种遍布北方 约有80种已被命名和描述 多年来，主要是短暂的，在许多情况下， 不可靠的，环境引起的变化。 斯托默博士是 用傅立叶变换发展形态测量程序 用于在光学显微镜下快速测量细胞 轮廓和其他细胞壁特征，以界定这些方面， 不太容易被瞬态改变尺寸和形状 水的条件，因此可以作为稳定的标记物， 特定的物种。 硅藻的长期演化趋势 物种，与假定的遗传基础，然后可以研究， 不受环境局部变化的影响。 用于尺寸和形状分析的形态测量方法 应可用于其它硅藻群和其它 单细胞生物

Diatoms, unicellular algae with silica-rich cell walls that are intricately ornamented, are important ecological indicators of water quality and nutrient status, with individual species adapted to particular conditions. Their use as indicators depends upon a reliable classification of the species, using stable morphological features of the cell wall. Diatom cell walls are easily preserved as fossils, for example in lake-bed cores, and make possible the analysis of very long-term changes in species composition and abundance, a task again dependent upon reliable taxonomic markers. Dr. Eugene Stoermer of the University of Michigan is studying freshwater diatoms of the genus Tabellaria to assess the limits of morphological variability within and between species of this group. Tabellaria species are found throughout the northern hemisphere, and about 80 species have been named and described over the years, mostly briefly and in many cases on the basis of unreliable, environmentally induced variations. Dr. Stoermer is developing morphometric procedures using Fourier transformations for the rapid measurement, under the light microscope, of cell outline and other cell-wall features, to delimit those aspects of size and shape that are less prone to modification by transient water conditions, and can thus be used as stable markers of particular species. Long-term evolutionary trends among diatom species, with a presumed genetic basis, can then be studied, uncomplicated by variations locally induced by the environment. The morphometric methods developed for size and shape analysis should be useful with other groups of diatoms and other unicellular organisms.