Section of Ecology and Taxonomy, Department of Biology, National and Kapodistrian University of Athens, Athens, Greece.
Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research, Anavyssos Attica, Greece.
Integr Zool. 2022 Sep;17(5):804-824. doi: 10.1111/1749-4877.12594. Epub 2021 Nov 8.
Crete with its complex geomorphological history is the island with the highest number of endemism observed in animal and plant taxa throughout the Aegean archipelago. While other groups of organisms within Crete are well-studied, the freshwater gastropod fauna still remains poorly investigated. Bythinella and Pseudamnicola, are 2 genera of freshwater springsnails, both present on the island, inhabiting springs and other freshwater habitats. Here, we conduct a comprehensive study on the distribution of the different genetic lineages of the 2 gastropod genera in order to assess the mode of their differentiation on the island and infer the actual number of species present in the island. Towards these aims, sequence data from the mitochondrial gene were used and analyzed within a phylogenetic framework. For Bythinella, our results strongly support at least 5 delineated Bythinella spp. inhabiting Crete, which correspond to the already described species from previous studies with the addition of a new one. Bythinella analyses reveal an old time-frame of differentiation with vicariant phenomena being more likely the main drivers shaping the present-day distribution of the genus' genetic lineages. For Pseudamnicola, our data indicate the presence of at least 2 delineated Pseudamnicola spp. with a differentiation more consistent to an isolation-by-distance pattern of a relatively recent origin. Dispersion processes followed by isolation of the populations and/or recent speciation, seem to be the underlying process for the current distribution of Pseudamnicola lineages.
克里特岛拥有复杂的地貌历史，是整个爱琴海群岛中动物和植物分类群中特有现象最频繁的岛屿。虽然克里特岛的其他生物群体已经得到了很好的研究，但淡水腹足纲动物群仍然研究不足。Bythinella 和 Pseudamnicola 是两种淡水泉蜗牛属，都存在于该岛上，栖息于泉水和其他淡水栖息地。在这里，我们对这两种腹足纲动物属的不同遗传谱系的分布进行了全面研究，以评估它们在岛上的分化方式，并推断出该岛实际存在的物种数量。为此，我们使用来自线粒体基因的序列数据，并在系统发育框架内进行了分析。对于 Bythinella，我们的研究结果强烈支持至少有 5 种已描述的栖息在克里特岛的 Bythinella spp.，其中包括之前研究中已经描述的物种，以及一种新的物种。Bythinella 的分析结果显示出一个古老的分化时间框架，地理隔离现象更有可能是形成该属遗传谱系目前分布的主要驱动因素。对于 Pseudamnicola，我们的数据表明至少有 2 种已描述的 Pseudamnicola spp.存在，其分化更符合相对较近起源的隔离距离模式。种群的扩散过程以及随后的隔离或最近的物种形成，似乎是目前 Pseudamnicola 谱系分布的潜在过程。
