Taxonomic And Phylogenetic Studies On Trimeresurus(S.L.) (Serpentes: Crotalinae)

Trimeresurus (sensu lato) is a large Asian pit viper genus that consists of over 40 species, it arranges over southern Asia, eastern Asia, and southeastern Asia. The species of this group display abundant diversity in distribution, lifestyles, and reproductive modes. First, in their distribution, some species are widely distributed, some restricted; some are found only at high altitude, but some at low altitude. Second, in lifestyles, some species are mainly terrestrial, some semi-arboreal, and others exclusively arboreal. In reproductive modes, oviparous and ovoviviparous are present. Originally all considered congeneric, six genera are generally recognized (Trimeresurus sensu stricto, Ovophis, Protobothrops, Zhaoermia, and Tropidolaemus). More recently, several genera were proposed for some members of Trimeresurus (sensu stricto) and Ovophis on the basis of hemipenial comparison and molecular analysis.In past several decades, considerable progress has been made on resolving the systematics of the Asian pitvipers of the Trimeresurus complex based on morphological, chromosomal, and molecular studies. However, there is considerable confusion and disagreement about the content of the proposed genera, the systematic position of some rare and restricted species, the intraspecific relationships of some widespread species, and in particular, the diagnosed characters of some genera and species.At present work, the comparison of hemipenis (10 species) and skull(9 species) are conducted; Also the molecular phylogeny of 43 species of Trimeresurus (sensu lato) is re-analyzed using Maximum-parsimony (MP), Maximum-likelihood (ML), and Bayesian (BI) approaches based on three mitochondrial gene fragments (12S rRNA, 16S rRNA, cytochrome b). The , main aim is to: 1..re-evaluate the phylogenetic relationships of Trimeresurus (sensu lato); 2. clarify the systematic position of several rare species; 3. preliminarily study on the intraspecific relationships of some widespread species; provide some morphological diagnosed characters for genera and species.1. Trimeresurus (sensu lato) is paraphyletic, and consists of two major groups: the arboreal group and terrestrial group;2. Both hemipenial comparison and molecular phylogeny results supports the revised taxonomies proposed by previous work (Malhotra and Thorpe, 2004a);3. The monophyly of Protobothrops is further supported; xiangchengensis should be a member of Protobothrops, it is distinctly different from P.. mucrosquamatus and closely related to P. jerdonii; the intraspecific relationships of P. jerdonii is unresolved;4. Triceratolepidophis, Zhaoermia, Protobothrops share several morphological characters, and form a monophyly with highly supported value in molecular analysis; kaulbacki, which was previously placed to Protobothrops, is the sisterhood with Triceratolepidophis sieversorum , it should be removed to Triceratolepidophis;5. Morphological and molecular data indicate that zayuensis and monticola are distinct, but closely related species; The name Ovophis should now include three species: monticola, zayuensis, tonkinensis;6. The intraspecific molecular phylogeny of Trimeresurus stejnegeri is inconsistent with that of morphology, a further study of this widespread species is high desirable;7. Two populations of Trimeresurus yunnanensis (one is from Yunnan and the other is from Sichuan) are much different in morphology and molecular phylogeny; the sample from Sichuan maybe is a cryptic species.