A new species of Psammophis (Serpentes: Psammophiidae) from the Turpan Basin in northwest China

In order to study the diversity, phylogenetic relationships and distribution of marsh frogs of the Pelophylax ridibundus complex in Kazakhstan and northwest China, we conducted phylogeographic analyses of 125 samples from 53 localities using the mtDNA ND2 and COI genes and the SAI nuclear gene sequences. Phylogenetic inference of mtDNA revealed three main lineages—sister lineages Balkhash and Syrdarya (as the Central Asian P. sp. novum), and the Anatolian P. cf. bedriagae, while from nDNA data, we additionally detected the western form, P. ridibundus. According to mtDNA data, the mean genetic distances between P. sp. novum and two other forms of marsh frogs was more than 5%. Genetic homogeneity within populations of the Syrdarya lineage and P. cf. bedriagae is characterized by low nucleotide diversity and high haplotype diversity. Demographic analyses of the lineages showed past population expansions of the Balkhash and the Syrdarya forms. Divergence from the most recent ancestor had occurred in the Early Pleistocene period (2.46 Mya) for the Balkhash and the Syrdarya lineages, and 1.27 Mya for the P. cf. bedriagae. Our findings provide a first investigation of the lineage diversification and population dynamics of the Central Asian marsh frogs and will be useful for further taxonomic implications and conservational actions.

The agamid lizard Phrynocephalus melanurus is restricted to Northwest China (Dzungar Basin) and the adjacent Eastern Kazakhstan (Zaisan and Alakol basins). To elucidate the phylogeography of P. melanurus, we obtained the mitochondrial DNA COI segments of 175 sampled lizards from 44 localities across the whole distribution. Phylogenetic analyses revealed two main Clades comprising five geographically structured lineages (I, IIa, IIb1, IIb2, and IIb3) that fit an isolation-by-distance (IBD) model. The divergence from the most recent common ancestor was dated to ~1.87 million years ago (Ma). Demographic analyses demonstrated lineage-specific response to past climate change: stable population for Clade I, Subclade IIb1; past population expansion for IIb3 since 0.18 Ma, respectively. Bayesian phylogeographic diffusion analyses detected initial spreading at the Saur Mount vicinity, approximately 1.8 Ma. Historical species distribution model (SDM) projected expansion of the suitable habitat in the last interglacial and shift and contraction in the last glacial maximum and Holocene epochs. The SDM predicted a drastic reduction in suitable area throughout the range as a response to future climate change. Our findings suggest that the evolution of P. melanurus followed a parapatric divergence with subsequent dispersal and adaptation to cold and dry environments during the Quaternary. Overall, this work improves our understanding of the lineage diversification and population dynamics of P. melanurus, providing further insights into the evolutionary processes that occurred in Northwest China and adjacent Eastern Kazakhstan.

Background: Comparative studies of selection pressures on mitochondrial genomes and protein-coding genes (PCGs) are scarce in the genus Teratoscincus (Strauch, 1863), particularly within Sphaerodactylidae. Given their close evolutionary relationship, Teratoscincus przewalskii (Strauch, 1887) and Teratoscincus roborowskii (Bedriaga, 1906) serve as ideal models for the characterization of mitochondrial genome sand analysis of selective pressure in this genus. Methods: In this study, we employed Sanger sequencing to sequence the mitochondrial genome of T. roborowskii (Bedriaga, 1906), and utilized sliding window analysis, selection pressure analysis etc. to compared it with that of its close relative, T. przewalskii (Strauch, 1887). Results: The results contain the genome composition, Ka/Ks values, AT/GC-skew, etc. Selection pressure analysis of PCGs across Teratoscincus (Strauch, 1863) species (including those in GenBank) revealed that most genes evolve slowly, with the exception of ATP8 and ND6, which exhibited faster evolutionary rates. Notably, the ND6 of T. roborowskii (Bedriaga, 1906) demonstrated rapid non-synonymous substitution rates which may contribute to the survival and reproductive success of the species by favoring advantageous mutations. Phylogenetic analysis for the mitochondrial genomes of Sphaerodactylidae, Phyllodactylidae, and Gekkonidae confirmed the distinctiveness of Sphaerodactylidae and the two Teratoscincus (Strauch, 1863) species. Conclusions: This study has advanced the understanding of adaptive evolution in Teratoscincus (Strauch, 1863) mitochondrial genomes, expanded the mitochondrial database of Sphaerodactylidae, and provided insights into the phylogenetic relationships of the genus.

A complete mitogenome of the Przewalski’s Wonder Gecko (Teratoscincus przewalskii) from the Junggar Basin in Northwest China was determined by using polymerase chain reaction and directly sequenced with the primer walking method. The total length was 17,184 bp, containing 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and a control region (CR). The order and structure of the genes were identical to those of congeners. The 13 PCGs contain four start codons (ATG, GTG, ATA, and ATC), three complete stop codons (TAA, TAG, and AGG), and two incomplete stop codons (T–, TA-). The concatenated PCGs were used to perform Bayesian phylogenetic analyses together with mitogenome data of the family Sphaerodactylidae and related representative taxa available in GenBank. The resulting tree recovered the monophyly of Sphaerodactylidae, and confirmed the sister relationship between T. przewalskii and T. roborowskii with strong support. The newly determined mitogenome will provide fundamental data for understanding the population genetic structure of T. pzrewalskii in particular, and the mitochondrial DNA evolution in Sphaerodactylidae in general.

Invasive species impact both the local biota and human economies and are a very serious threat to biodiversity. The American bullfrog was initially introduced into northwestern China and many other sites for aquacultural purposes. Then, the frogs escaped and established feral populations. Here, we investigated the variations in age, body size, and sexual size dimorphism of two breeding populations inhabiting the southern (warm and dry) and northern (cold and wet) regions of Xinjiang province in northwestern China. Both populations originated from a single source that was introduced into Xinjiang 54 years ago. In both populations, males were significantly smaller than females, indicating significant sexual size dimorphism. The mean age and body size of both sexes in the population in the colder region were lower than those of the population in the warmer region. Bullfrogs in the southern population had a higher degree of sexual size dimorphism. These results increase our understanding of the American bullfrog, which could help in the development of strategies to control this invasive species.