Publication details
Resolving taxonomic uncertainty in the Euconulus fulvus group (Gastropoda): Evidence for the reclassification of Parakaliella harimensis
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| Year of publication | 2025 |
| Type | Appeared in Conference without Proceedings |
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| Description | Euconulus is one of the most widely distributed genera of land snails across the Holarctic and is characterized by species with simple, tightly coiled, conical shells, typically between 2.3 and 3.5 mm in diameter. About ten nominal Euconulus species have been described from the Holarctic, however, there are several unresolved taxonomical questions. For instance, based on previous publications, Euconulus fulvus (Müller, 1774), appeared to have a polyphyletic structure, including a distinct subclade originating from Japan. More data was needed to promote the Japanese clade to a new species. By including more samples from Japan and Southeast Asia we aim to explore the taxonomic status of this clade further using an integrative approach. Two nuclear (ITS1, ITS2) and two mitochondrial (COII, 16S) markers were used to reconstruct the phylogenetic relationships of the genus Euconulus using 53 samples of all five nominal species from the E. fulvus group. Additionally, we used two newly developed nuclear markers (ZN507 + TEP1) to get a better-resolved phylogenetic tree. We approached the aim by conducting morphometric analysis, utilizing conventional shell measurements and geometric morphometry with 19 landmarks. Based on phylogenetic tree reconstruction we documented six distinct groups. The group comprising populations from East and Southeast Asia displayed substantial genetic divergence and notably distinct shell morphology compared to all other species. There was a convincing morphological similarity between this group and Parakaliella harimensis, which was confirmed by including a lectotype and paralectotype of P. harimensis in geometric morphometry analysis. We, therefore, suggest changing the taxonomical name of P. harimensis to Euconulus harimensis. Interestingly, we found a remarkable genetic intraspecific variability of this species, which we attribute to the Pleistocene climatic dynamic in this region, compared to the other, widely distributed, sister species. |