In this study we investigated the morphology and ecology of representatives of the taxonomically ambiguous genus Trochulus. The main focus was on the T. hispidus complex, which comprises several genetically highly divergent mitochondrial clades, as determined in a parallel molecular genetic study. We analysed shell morphology and anatomical traits and asked whether the clades are differentiated in these characters. In addition, the related species T. oreinos and T. striolatus were investigated and compared with the T. hispidus complex. Finally, we compared the ecological requirements of the taxa. Among the genetic clades of the T. hispidus complex there was no clear morphological differentiation and geographic populations could not be distinguished based on their morphology. The investigated characters of the genital anatomy did not allow discrimination of any of the T. hispidus clades and were not even diagnostic for the group as a whole. The morphotype of T. sericeus is present in all clades and thus cannot be assigned to a genetic group or any specific population. Thus, our morphological data do not provide evidence that any of the mitochondrial T. hispidus clades represent separate species. Concerning interspecific delimitation, the T. hispidus complex was clearly differentiated from T. striolatus and T. oreinos by shell morphological and anatomical characters, e.g. sculpture of shell surface and details of the penis. Finally, the habitat of T. oreinos is different from those of the other two species. In contrast to the lack of correspondence between genetic and morphological differentiation within the T. hispidus complex, related species display intraspecific morphological differentiation corresponding with mitochondrial clades: within T. striolatus there was a slight morphological differentiation between the subspecies T. s. striolatus, T. s. juvavensis and T. s. danubialis. The two subspecies of T. oreinos could be discriminated by a small but consistent difference in the cross-section of the penis. The unequal levels of intraspecific differentiation are caused by different evolutionary histories as a consequence of disparities in ecological demands, dispersal ability and use of glacial refugia: both the T. hispidus complex and T. striolatus are fast-spreading, euryoecious organisms which are able to (re-)colonize habitats and survive under different climate conditions. While the T. hispidus complex probably survived the Pleistocene in several glacial refugia, for T. striolatus one glacial refugium is suggested. Trochulus oreinos differs from the other taxa, as it is a slow disperser with a narrow ecological niche. We suggest that its subspecies spent at least the last glaciation in or close to the presently inhabited areas.

中文翻译：

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Trochulus hispidus 复合体和相关类群（肺类：Hygromiidae）的分化：形态学、生态学及其与系统发育地理学的关系


在这项研究中，我们研究了分类学上不明确的 Trochulus 属代表的形态和生态学。主要焦点是 T. hispidus 复合体，它由几个遗传上高度分化的线粒体进化枝组成，这是在一项平行分子遗传学研究中确定的。我们分析了贝壳的形态和解剖特征，并询问进化枝在这些特征上是否存在分化。此外，还对相关物种 T. oreinos 和 T. striolatus 进行了研究，并与 T. hispidus 复合体进行了比较。最后，我们比较了类群的生态要求。在T. hispidus复合体的遗传进化枝中，没有明显的形态分化，无法根据形态区分地理种群。所研究的生殖器解剖特征不允许区分任何毛毛毛虫分支，甚至不能对整个群体进行诊断。 T. sericeus 的形态型存在于所有进化枝中，因此不能归属于某个遗传群体或任何特定群体。因此，我们的形态学数据没有提供证据表明任何线粒体 T. hispidus 分支代表不同的物种。关于种间界限，T. hispidus 复合体通过壳的形态和解剖特征（例如壳表面的雕刻和阴茎的细节）与 T. striolatus 和 T. oreinos 明显区分。最后，T. oreinos 的栖息地与其他两个物种不同。与 T. hispidus 复合体内遗传和形态分化之间缺乏对应关系相反，相关物种表现出与线粒体进化枝相对应的种内形态分化：在 T. hispidus 内。 striolatus 亚种之间存在轻微的形态差异。 striolatus，T. s。 juvavensis 和 T. s.丹努比亚利斯。 T. oreinos 的两个亚种可以通过阴茎横截面的微小但一致的差异来区分。种内分化水平的不平等是由不同的进化历史造成的，这是生态需求、扩散能力和冰川避难所使用差异的结果：T. hispidus Complex和T. striolatus都是快速传播的广性生物，能够（重新）殖民栖息地并在不同的气候条件下生存。虽然 T. hispidus 复合体可能在更新世的几个冰川避难所中幸存下来，但对于 T. striolatus 来说，建议存在一个冰川避难所。 Trochulus oreinos 与其他类群不同，因为它是一种缓慢的扩散者，具有狭窄的生态位。我们认为，它的亚种至少在目前居住的地区或附近度过了最后一次冰期。