We report the discovery of three new species of freshwater metopid ciliates, Pileometopus lynni gen. et sp. nov., Castula flexibilis gen. et sp. nov., and Longitaenia australis gen. et sp. nov. Based on morphologic features and the 18S rRNA gene phylogeny, we transfer two known species of Metopus to the new genus Castula, as C. fusca (Kahl, 1927) comb. nov. and C. setosa (Kahl, 1927) comb. nov. and another known species is herein transferred to the new genus Longitaenia, as L. gibba (Kahl, 1927) comb. nov. Pileometopus is characterized by a turbinate body shape, a dorsal field of densely spaced dikinetids, a bipartite paroral membrane, and long caudal cilia. A distinctive morphologic feature of Castula species is long setae arising over the posterior third of the body (as opposed to a terminal tuft). Longitaenia spp. are characterized by an equatorial cytostome and long perizonal ciliary stripe relative to the cell length. Based on phylogenetic analyses of 18S rRNA gene sequences, we identify and briefly discuss strongly supported clades and intraspecific genetic polymorphism within the order Metopida.

我们报告发现了三个新物种的淡水类比缘纤毛虫，Pileometopus lynni gen。等。十一月，Castula flexibilis gen。等。十一月，和澳大利亚Longitaenia gen。等。十一月 基于形态特征和18S rRNA基因系统发育，我们将两种已知的Metopus物种转移至Castus属，如C. fusca（Kahl，1927年）。十一月 和C. setosa（Kahl，1927年）梳理。十一月 和另一种已知的物种在本文中被转移到新的属Longitaenia，如L. gibba（卡尔，1927）梳。十一月 堆肥其特征是鼻甲状，背侧密集的双歧动物，双壁壁膜和长尾纤毛。Castula种类的一个独特的形态特征是在身体后三分之一（与末端簇相反）上出现的长刚毛。ita虫属 其特征是相对于细胞长度的赤道细胞沉积和长的睫状睫状体条纹。基于对18S rRNA基因序列的系统发育分析，我们确定并简要讨论了Metopida内强力支持的进化枝和种内遗传多态性。