Until recently it seemed that amoebae of the genus Thecamoeba can be reliably identified using light-microscopic characters, like the size and shape of the cell, a characteristic pattern of folds and ridges and structure of the nucleus. However, recent molecular studies show the presence of sibling species that can be reliably distinguished based on the gene sequence data only. Here we describe a new terrestrial species, Thecamoeba foliovenanda n. sp. This species is almost identical with Thecamoeba similis in light-microscopy, which has minor differences in the ultrastructure but considerable differences in the SSU rRNA gene sequence. We investigated the light-microscopic data, as well as transmission electron-microscopic images and videorecords on the type strain of T. similis 1583/8 and performed its comparison with the new species. This study further supports the conclusion that species of the genus Thecamoeba nowadays require gene sequencing for reliable identification and species distinction.

直到最近，似乎仍可以使用光镜特征可靠地鉴定出Thecamoeba属的变形虫，例如细胞的大小和形状，褶皱和脊的特征性模式以及细胞核的结构。但是，最近的分子研究表明，仅基于基因序列数据就可以可靠地区分同胞物种。在这里，我们描述了一个新的陆地物种，Thecamoeba foliovenanda n。sp。该物种与Thecamoeba similis几乎相同在光学显微镜下，其超微结构差异很小，但SSU rRNA基因序列差异很大。我们调查了T. similis 1583/8型菌株的光显微数据以及透射电子显微图像和录像，并将其与新物种进行了比较。这项研究进一步支持了这样的结论，即Thecamoeba属的物种如今需要进行基因测序才能可靠地鉴定和区分物种。