Taxonomic status of the Central Asian damselfly Calopteryx samarcandica Bartenev, 1912 (Odonata: Calopterygidae)

Abstract

The taxonomic status of the Central Asian damselfly Calopteryx samarcandica was determined on the basis of molecular and phenotypic data from the Kugitang Mountains, SE Uzbekistan. Molecular analyses (COI and 18S rDNA, ITS1-5.8S rDNA-ITS2) revealed that C. samarcandica forms part of a clade that includes taxa treated in the literature as subspecies of Calopteryx splendens and/or related species. However, both mitochondrial and nuclear DNA confirmed that C. samarcandica deserves separate species status. The COI distance to C. splendens (including C. xanthostoma) is moderate (3.47%, K2P), but much greater than the internal distances between the sequences qualified in C. splendens (0.4%); this difference is supported by the low values of the barcoding gap in this genus. The rather distant separation of C. samarcandica from both C. splendens (ancilla, taurica, intermedia) and C. orientalis and the length of the samarcandica-branch recognisable in nuclear rDNA strengthen the independent position of the first species. The phylogenetic position of C. samarcandica in the genus Calopteryx remains unclear due to the low variability of nuclear rDNA markers and insufficient and partly incomparable data for other taxa. The molecular data support the phenotypic and ecological specificity of C. samarcandi­ca, defined by a diagnostic combination of its traits (male and female wing colours and large size and basal diffusion of the wing spot in males) and the conservative association with groundwater-fed natural watercourses in the mountains and foothills fringing the vast Central Asian mountain block.