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| Cultellus exilis Yu, Jiao & Zhang, 2024 |
Abstract
The present study describes a new species within the genus Cultellus Schumacher, 1817 collected from the South China Sea. An integrative taxonomic approach incorporating morphological comparisons, geometric morphometrics and genetic analyses was used to identify and differentiate the new species. Cultellus exilis sp. nov. is distinguished from its congeners by its slender, fragile and translucent valves, curved posteroventral margins and relatively large protractor scars. The geometric morphometric analyses, based on outlines data, indicated that samples of Cultellus exilis sp. nov. clustered together and were distinctly separated from other species. Multiple species delimitation results, based on the mitochondrial COI gene, support the separation of Cultellus exilis sp. nov. from its related congeners. Phylogenetic analyses of a nuclear (28S rRNA) and two mitochondrial (COI, 16S rRNA) genes using Maximum Likelihood and Bayesian Inference methods revealed that the species belongs to the genus Cultellus. The superfamily Solenoidea Lamarck, 1809, which includes the families Solenidae Lamarck, 1809 and Pharidae H. Adams & A. Adams, 1856, exhibits closer affinity to the family Hiatellidae Gray, 1824 than to Solecurtidae d’Orbigny, 1846. Furthermore, we found that the genus Siliqua was clustered alongside the genera Ensiculus and Phaxas as a sister clade, which contradicts the current systematics of the subfamily within the family Pharidae. This work highlights the utility of integrative taxonomy for species identification, recognition and phylogenetic investigation.
Key Words: geometric morphometrics, integrative taxonomy, Pharidae, phylogeny, Solenoidea, species delimitation
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| Cultellus exilis sp. nov. (holotype) A, B. MBM229032, L = 34.66 mm; C, D. Exterior views of left and right valve; E, F. Interior views of left and right valve; H. Hinge of left valve; I. Hinge of right valve; J. Internal radial rib of left valve. |
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| Cultellus exilis sp. nov. (paratypes) A–D. MBM264485; E–H. MBM264488; I–L. MBM264497; M–P. MBM264500; Q–T. MBM229040. Scale bars: 10 mm. |
Cultellus exilis sp. nov.
Etymology: The specific epithet “exilis” is derived from the Latin, referring to its slender shell, which is a remarkable difference from other species in this genus.
Yanan Yu, Yingyi Jiao and Junlong Zhang. 2024. Description of A New Species of the Genus Cultellus Schumacher, 1817 (Bivalvia, Pharidae) from the South China Sea, based on integrative taxonomy. Zoosystematics and Evolution. 100(2): 425-436. DOI: 10.3897/zse.100.113972
