Parakaliella harimensis from East Asia: A Highly Diverse Euconulus Lineage

KAFIMOLA, Sara; Veronika HORSÁKOVÁ; Kazuki KIMURA; Jeffrey Clark NEKOLA a Michal HORSÁK. Parakaliella harimensis from East Asia: A Highly Diverse Euconulus Lineage. In The Meeting of the Society Mollusc Research Austria (MoFA), Linz, Austria. 2025.

Základní údaje

Originální název

Parakaliella harimensis from East Asia: A Highly Diverse Euconulus Lineage

Název anglicky

Parakaliella harimensis from East Asia: A Highly Diverse Euconulus Lineage

Autoři

KAFIMOLA, Sara; Veronika HORSÁKOVÁ; Kazuki KIMURA; Jeffrey Clark NEKOLA a Michal HORSÁK

Vydání

The Meeting of the Society Mollusc Research Austria (MoFA), Linz, Austria, 2025

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Prezentace na konferencích

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není předmětem státního či obchodního tajemství

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Anotace

V originále

Parakaliella harimensis from East Asia: A Highly Diverse Euconulus Lineage Sara Kafimola1, Veronika Horsakova1, Kazuki Kimura2, Jeffrey C. Nekola1 & Michal Horsak1 1 Department of Botany and Zoology, Masaryk University, Kotlářská 2, Brno, CZ-61137, Czech Republic 2 Center for Northeast Asian Studies, Tohoku University, Kawauchi 41, Sendai, 980-0862, Japan Email: [e-mail] Euconulus is a widespread Holarctic land snail genus, characterized by small, tightly coiled conical shells ranging from 2.3 to 3.5 mm. Genetic studies often show that species with similar shells belong to separate lineages, reflecting convergent evolution rather than common ancestry. As a result, some species classified as Euconulus may belong to other related genera, and vice versa. Additionally, many taxonomic questions about this genus remain unresolved. For example, earlier studies indicated that Euconulus fulvus (Müller, 1774) exhibits a polyphyletic structure, with a distinct subclade originating in Japan. However, additional data were required to elevate the Japanese lineage to species level. To further clarify the taxonomic status of this clade, we added samples from Japan and Southeast Asia and used an integrative approach. Phylogenetic relationships in Euconulus were reconstructed using two nuclear (ITS1, ITS2) and two mitochondrial (COII, 16S) markers from 53 samples across all five E. fulvus species. To have a better resolved tree, two new nuclear markers, ZN507 and TEP1, were also included. To proceed, we performed morphometric analyses combining shell measurements and geometric morphometry using 19 landmarks. The group containing populations from East and Southeast Asia showed significant genetic divergence and markedly different shell morphology compared to the other species. This group showed a strong morphological resemblance to Parakaliella harimensis reported from Japan, confirmed through geometric morphometry using its lectotype and paralectotype. Therefore, we propose reclassifying Parakaliella harimensis as Euconulus. Examination of type specimens of several Parakaliella species revealed that the same species has been described multiple times, primarily due to assumptions about frequent island endemism. This highlights that unrelated snail species can evolve similar shell shapes under similar selective pressures, leading to taxonomic misclassification. Notably, this species shows high genetic variability, likely promoted by climatic stability of the area during Pleistocene, unlike its more widespread sister species.

Anglicky

Parakaliella harimensis from East Asia: A Highly Diverse Euconulus Lineage Sara Kafimola1, Veronika Horsakova1, Kazuki Kimura2, Jeffrey C. Nekola1 & Michal Horsak1 1 Department of Botany and Zoology, Masaryk University, Kotlářská 2, Brno, CZ-61137, Czech Republic 2 Center for Northeast Asian Studies, Tohoku University, Kawauchi 41, Sendai, 980-0862, Japan Email: [e-mail] Euconulus is a widespread Holarctic land snail genus, characterized by small, tightly coiled conical shells ranging from 2.3 to 3.5 mm. Genetic studies often show that species with similar shells belong to separate lineages, reflecting convergent evolution rather than common ancestry. As a result, some species classified as Euconulus may belong to other related genera, and vice versa. Additionally, many taxonomic questions about this genus remain unresolved. For example, earlier studies indicated that Euconulus fulvus (Müller, 1774) exhibits a polyphyletic structure, with a distinct subclade originating in Japan. However, additional data were required to elevate the Japanese lineage to species level. To further clarify the taxonomic status of this clade, we added samples from Japan and Southeast Asia and used an integrative approach. Phylogenetic relationships in Euconulus were reconstructed using two nuclear (ITS1, ITS2) and two mitochondrial (COII, 16S) markers from 53 samples across all five E. fulvus species. To have a better resolved tree, two new nuclear markers, ZN507 and TEP1, were also included. To proceed, we performed morphometric analyses combining shell measurements and geometric morphometry using 19 landmarks. The group containing populations from East and Southeast Asia showed significant genetic divergence and markedly different shell morphology compared to the other species. This group showed a strong morphological resemblance to Parakaliella harimensis reported from Japan, confirmed through geometric morphometry using its lectotype and paralectotype. Therefore, we propose reclassifying Parakaliella harimensis as Euconulus. Examination of type specimens of several Parakaliella species revealed that the same species has been described multiple times, primarily due to assumptions about frequent island endemism. This highlights that unrelated snail species can evolve similar shell shapes under similar selective pressures, leading to taxonomic misclassification. Notably, this species shows high genetic variability, likely promoted by climatic stability of the area during Pleistocene, unlike its more widespread sister species.