Molecular phylogeography of endangered sharp-snouted pitviper (Deinagkistrodon acutus; Reptilia, Viperidae) in Mainland China Song Huang a,b,c , Shunping He b, * , Zuogang Peng b , Kai Zhao b , Ermi Zhao a, * a School of Life Sciences, Sichuan University, Chengdu 610064, China b Laboratory of Fish Phylogenetics and Biogeography, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China c Department of Biology, Huangshan University, Huangshan 245021, China Received 6 August 2006; revised 3 April 2007; accepted 23 May 2007 Available online 9 June 2007 Abstract Using phylogenetic and population genetic approaches, the present study reports the phylogeographic structure of the sharp-snouted pitviper (Deinagkistrodon acutus), a threatened snake species with commercial and medicinal importance in China. The entire mitochon- drial ND2 gene (NADH dehydrogenase subunit 2) sequences of 86 individuals of D. acutus from 14 localities across its range in China were determined. Based on the results of phylogenetic analyses, distribution of diagnostic sites, haplotype network, and AMOVA hier- archical analysis, an east–west division of the whole D. acutus population could be observed. Geographically, a line formed by a lake, river, and mountain chain (the Poyang Lake, Gan River to the southern end of the Wuyi Mountains), results in vicariance and approx- imately vertically splits the range into two and the whole population into two main lineages (western and eastern). The bifurcating tree suggested generally west to east dispersal trend. The data fit the isolation by distance (IBD) model well. Star-like clusters in haplotype network, significantly negative values of Fs statistics, and unimodal mismatch distributions all suggest recent demographic expansions in four areas. The results show that isolation, dispersal, bottleneck, and expansion jointly constitute the history of D. acutus. In a haplotype network, the excessive predominance of central haplotypes, few medium-frequency haplotypes, predominance (73.1%) of the singletons among the derived haplotypes, most of which are connected to the central haplotype by only one mutational step, unsymmetrical cam- panulate unimodal curve of mismatch distributions and leftwards shift of the peaks, all suggest that the whole D. acutus population is a young population with low genetic diversity. Based on the data, the first priority for conservation action should be given to the Huang- shan unit. Ó 2007 Elsevier Inc. All rights reserved. Keywords: Phylogeography; Deinagkistrodon acutus; Reptilia; ND2; Isolation; Dispersal; Expansion; Conservation 1. Introduction Studies on molecular phylogeography and conservation genetics have increased rapidly during the last decade. The information derived from molecular data of these studies, undetectable through traditional biogeography and demography, is essential to examining population dynam- ics and understanding evolutionary processes (Avise, 1994; Prior et al., 1997), and could provide the foundation for formulating and implementing any conservation and management plan (e.g., Frankham et al., 2002; Hrbek et al., 2005; Ma et al., 2006). In Mainland China, few such studies have been reported, and most of them involve endotherm species, fishes, and amphibians (e.g., Macey et al., 1998b; Murphy et al., 2000; Su et al., 2001; Pang et al., 2003; Perdices et al., 2004, 2005; Fu et al., 2005; Li et al., 2005; Zhao et al., 2005). Few such studies involve terrestrial poikilotherms with narrow habitat requirements and limited dispersal potentials such as venomous snakes; this is partly also due to their secretive habits, difficulty in obtaining representative samples (described by Ursenb- 1055-7903/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.ympev.2007.05.019 * Corresponding authors. Fax: +86 27 68780071 (S. He), +86 28 85222753 (E. Zhao). E-mail addresses: clad@ihb.ac.cn (S. He), zhaoermi@cib.ac.cn (E. Zhao). www.elsevier.com/locate/ympev Molecular Phylogenetics and Evolution 44 (2007) 942–952