ABSTRACT

The systematics of the gastropod clade Umbraculida, particularly the family Tylodinidae, has been a matter of debate. The Tylodinidae of the Mediterranean Sea are a case in point, with no comprehensive molecular assessment of diversity having been carried out to date. Several species and genera have been erected and synonymized in the course of the last two centuries and only a single species from each of the genera Tylodina and Anidolyta are considered to be present in these waters. In order to shed light on the controversial taxonomy of the group, we carried out both morpho-anatomical study and molecular analyses using fragments of two mitochondrial genes, cytochrome c oxidase subunit I and 16S rRNA, and the nuclear gene histone H3. Phylogenetic analyses and species delimitation tests clearly recovered two independent lineages of Tylodina from the Mediterranean and Eastern Atlantic coast, the type species T. perversa and the resurrected T. rafinesquii. We found clear differences in shell and radular morphology between both species, as well as differences in their habitat and food preferences. Interestingly, we found strong evidence that T. rafinesquii is sister to T. fungina from the Eastern Pacific rather than to the sympatric T. perversa. Furthermore, the new morphological data strongly encourage the suppression of the genus Anidolyta, which should be considered a junior synonym of Tylodina.

中文翻译：

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评估地中海和东部大西洋中的Ty科的系统学：1836年复活泰勒丁娜·菲利皮（Tylodina rafinesquii Philippi）（Heterobranchia：Umbraculida）

摘要

腹足纲进化支的伞形目，特别是Ty科（Tylodinidae）的系统学一直存在争议。例如，地中海的tylodinidae尚未进行全面的多样性分子评估。在最近的两个世纪中，已经建立了几种物种和属，并且它们是同义词，并且认为在这些水域中仅存在来自蒂罗迪纳属和Anidolyta属中的每个物种。为了阐明该组有争议的分类学，我们使用两个线粒体基因细胞色素c的片段进行了形态解剖学研究和分子分析。氧化酶亚基I和16S rRNA，以及核基因组蛋白H3。系统发育分析和物种定界测试清楚地从地中海和东大西洋沿岸恢复了泰罗迪纳的两个独立谱系，即物种颠倒的毛虫和复活的毛发的T. rafinesquii。我们发现两种物种的壳和胚根形态明显不同，以及它们的栖息地和食物偏好也不同。有趣的是，我们发现有力的证据表明T. rafinesquii是姐姐T. fungina从东太平洋，而不是同域T. perversa。此外，新的形态学数据强烈鼓励抑制该属Anidolyta，应该被认为是Tylodina的初级同义词。