Sampling locations and genetic differentiation among the investigated individuals. (A) Sampling locations with population assignment with K = 9. We collected 26 populations encompassing 7 species across Taiwan, including 4 sympatric populations and a S. tashiroi population collected from Orchid Islet. (B) PCA of all individuals in the space of the first two principal components and in the space of the second and the third principal components. (C) Assignments of each of the 504 individuals by the most-supported models with K = 2 and K = 9 genetic clusters. TAI, S. taiwanensis ; IND,S. indica ; PLA, S. playfairii ; AUS, S. austrotaiwanensis ; HSI, S. hsiehii ; TAS, S. tashiroi ; BAR, S. barbata .