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in J. Chen, Y. Chen, Tang, Lei, Yan et Song, 2023. |
Abstract
The Pseudogastromyzon genus, consisting of species predominantly distributed throughout southeastern China, has garnered increasing market attention in recent years due to its ornamental appeal. However, the overlapping diagnostic attributes render the commonly accepted criteria for interspecific identification unreliable, leaving the phylogenetic relationships among Pseudogastromyzon species unexplored. In the present study, we undertake molecular phylogenetic and morphological examinations of the Pseudogastromyzon genus. Our phylogenetic analysis of mitochondrial genes distinctly segregated Pseudogastromyzon species into two clades: the Pseudogastromyzon clade and the Labigastromyzon clade. A subsequent morphological assessment revealed that the primary dermal ridge (specifically, the second ridge) within the labial adhesive apparatus serves as an effective and precise interspecific diagnostic characteristic. Moreover, the distributional ranges of Pseudogastromyzon and Labigastromyzon are markedly distinct, exhibiting only a narrow area of overlap. Considering the morphological heterogeneity of the labial adhesive apparatus and the substantial division within the molecular phylogeny, we advocate for the elevation of the Labigastromyzon subgenus to the status of a separate genus. Consequently, we have ascertained the validity of the Pseudogastromyzon and Labigastromyzon species, yielding a total of six valid species. To facilitate future research, we present comprehensive descriptions of the redefined species and introduce novel identification keys.
Keywords: Labigastromyzon, mitochondrial genome, phylogeny, Pseudogastromyzon, taxonomy
Jingchen CHEN, Yiyu CHEN, Wenqiao TANG, Haotian LEI, Jinquan YAN and Xiaojing SONG. 2023. Resolving Phylogenetic Relationships and Taxonomic Revision in the Pseudogastromyzon (Cypriniformes, Gastromyzonidae) Genus: Molecular and Morphological Evidence for A New Genus, Labigastromyzon. Integrative Zoology. DOI: 10.1111/1749-4877.12761
This research elucidates the marked geographical delineation between Pseudogastromyzon and Labigastromyzon genera, with a limited overlapping region. The evolution of labial structures from elementary to intricate morphologies aligns with mitochondrial genome phylogenetics. Notably, the labial adhesive apparatus in Pseudogastromyzon exhibits unimodal and bimodal morphotypes, enhancing the accuracy and efficiency of species identification within this genus.
