3 RESULTS
The BI and ML analyses depicted relatively consistent topologies (Fig. 2). All species of Sibynophis formed a highly supported lineage. Sister species S. bistrigatus and S. subpunctatus were basal to the lineage, while all other specimens formed another monophyly with strong support. The Chinese specimens were positioned in four distinct but highly supported clades (A-D). Clade A was composed of specimens from eastern Yunnan and Guizhou, China; clade B consisted of samples from China (Xizang) and Myanmar; clade C contained specimens from China (Yunnan), Vietnam, Myanmar, and Cambodia; and clade D contained specimens from Vietnam and China (Sichuan, Shaanxi, and southern China). The four clades formed a highly supported monophyly with well-resolved interclade relationships (D, (A, (B, C))). A sample previously identified as S. collaris (CAS 240150) is much distinct from the other S. collaris identified samples (B clade).
Uncorrected p -distances between species and clades are listed in Table 2. The interspecific/clade genetic distances ranged from 8.3% (clades B and C) to 21.2% (clade B and S. bistrigatus ) based on cyt.b and from 7.9% (clades B and C) to 18.3% (clade D and sample CAS 240150) based on ND2 (Table 2).
The network inferred from the c-mos gene showed each species/clade exhibited unique haplotype, except clade B (S. collaris ), which shared a haplotype with clade C (S. triangularis ).Sibynophis c. grahami , S. c. chinensis , and S. triangularis contained three, two, and two unique haplotypes, respectively (Fig. 3).