Molecular Assessment and Taxonomic Status of the Rapid Racerunner (Eremias Velox Complex) with Particular Attention to the Populations in Northwestern China
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Asian Herpetological Research 2014, 5(1): 12–25 DOI: 10.3724/SP.J.1245.2014.00012 Molecular Assessment and Taxonomic Status of the Rapid Racerunner (Eremias velox complex) with Particular Attention to the Populations in Northwestern China Jinlong LIU1, 2, Natalia A. ANANJEVA3, Marina A. CHIRIKOVA4, Konstantin D. MILTO3 and Xianguang GUO1* 1 Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China 2 University of Chinese Academy of Sciences, Beijing 100049, China 3 Zoological Institute, Russian Academy of Sciences, St. Petersburg 199034, Russia 4 Institute of Zoology, Committee of Scienti¿c 0inistry of Education and Science, Almaty 050060, Kazakhstan Abstract The rapid racerunner, Eremias velox, is a widely distributed lizard from the northern Caucasus across entire Central Asia eastward to China. It is increasingly common to accept E. velox as a species complex in its entire range. To date, published morphological and molecular systematic hypotheses of this complex are only partially congruent, and its taxonomic status and evolutionary history are still far from clear. The mitochondrial cytochrome b gene and 12S rRNA sequences were used to evaluate the taxonomy of this complex, with particular attention to the phylogenetic placement of populations in northwestern China. Examination of the phylogenetic analyses recovers seven distinct, ELRJHRJUDSKLFDOO\GLVFUHWHDQGZHOOVXSSRUWHGFODGHVUHYHDOLQJJHQHWLFDOO\LGHQWL¿DEOHSRSXODWLRQVFRUUHVSRQGLQJWR VRPHSUHYLRXVO\PRUSKRORJ\GH¿QHGVXEVSHFLHV&KLQHVHE. v. roborowskii appears to have split from other Central $VLDQUDSLGUDFHUXQQHUOL]DUGVZHOOEHIRUHGLIIHUHQWLDWLRQRFFXUUHGDPRQJWKHODWWHUWD[D6SHFL¿FDOO\ZHFRUURERUDWH that there are two subspecies occurring in China, i.e., E. v. velox and E. v. roborowskii. We recommend a novel VXEVSHFL¿FVWDWXVIRUWKHSKHQRW\SLFDOO\DQGJHQHWLFDOO\GLVWLQFWSRSXODWLRQVLQVRXWKHUQ$UDO6HDUHJLRQRI8]EHNLVWDQ previously assigned to E. v. velox. Finally, each of the three independently evolving lineages from Iranian Plateau should be recognized as three species new to science under the general lineage concept. Keywords mtDNA, subspecies, Eremias velox complex, taxonomy, phylogeography 1. Introduction been assigned to the genus, and much of their phylogeny and taxonomy is controversial (e.g., Szczerbak, 1974; Racerunner lizards of the genus Eremias (family Guo et al., 2011). Among the many controversies, the Lacertidae) are the dominant reptiles in the deserts and taxonomy of the Eremias velox complex is perhaps one steppes of Central Asia. The taxonomy of this genus has of the most confusing. The distribution of this group a long complex history, and the delimitation of species/ ranges from the northern Caucasus across entire Central subspecies of Eremias is known for being notoriously Asia eastward to China (Figure 1). Traditionally, the rapid GLI¿FXOW7KLVLVLQSDUWFDXVHGE\WKHJUHDWJHRJUDSKLF racerunner was considered as a single species with three variation in most morphological characters in many of or four described subspecies (Szczerbak, 1974, 1975; the species (e.g., Szczerbak, 1974, 1975; Ananjeva et al., (UHPFKHQNRDQG3DQ¿ORY +RZHYHUDVQRWHGE\ 1998; Chirikova, 2004). Currently, over 36 species have Rastegar-Pouyani (2009), it is increasingly common to * Corresponding author: Dr. Xianguang GUO, from Chengdu Institute of accept E. velox as a clade in its entire range representing a Biology, Chinese Academy of Sciences, with his research focusing on species complex. The nominate form occurs in the larger taxonomy, phylogeny and biogeography of reptiles. E-mail: [email protected] parts of the distribution range. The Caspian subspecies E. Received: 27 December 2013 Accepted: 1 March 2014 v. caucasia occurs at the western part of the range. The No. 1 Jinlong LIU et al. Molecular Assessment and Taxonomic Status of the Rapid Racerunner 13 subspecies E. v. roborowskii is endemic in Turpan-Hami analyses, Wang et al. (2014) argued that there is no Depression and Dunhuang Basin in northwestern China. subspecies differentiation between populations from 5HFHQWO\(UHPFKHQNRDQG3DQ¿ORY GHVFULEHGWKH Turpan-Hami Depression and from Dzungarian Basin fourth subspecies, E. v. borkini from the highlands of and Ily Valley in China. Thus, Wang et al. (2014) implied Issyk-Kul lake depression in Kyrgyzstan. that E. v. roborowskii may be a synonym of nominate Many recent taxonomic treatments reveal varied subspecies. opinions as to the number of species. Some herpetologists Establishing correct species/subspecies limits depends recognized a single widespread species (e.g., Szczerbak, on adequate sampling of populations throughout the 2003; Ananjeva et al., 2006; Sindaco and Jeremcenko, range. Given the previous studies, it might appear that 2008), whereas others (Rastegar-Pouyani, 2009; Rastegar- taxonomic limits were clear. Rastegar-Pouyani (2009) Pouyani et al., 2012) hypothesized the existence of at least made the first attempt to elucidate the phylogenetic four distinct species and three well-supported subspecies relationships among the rapid racerunner in Iran and (Figure 2). Some of the differences of opinion result Central Asia on the basis of ISSR-PCR fingerprints from the accumulation of mitochondrial DNA sequence data. The results were tentative due in part to limited information (Rastegar-Pouyani et al., 2012). At present taxonomic sampling. As shown by simulations and it seems reasonable that mtDNA sequence information empirical studies, more taxa and data do affect the supports the recognition of the Iranian populations of phylogenetic reconstruction (e.g., Pollock et al., 2002; E. velox as three distinct species based on differences in Zwickl and Hillis, 2002). Rastegar-Pouyani et al. (2012) distribution, morphology, habitat preference, and mtDNA studied patterns of mitochondrial DNA cytochrome b sequence divergence (Figure 2). (cyt b) and 12S rRNA variation in 70 specimens from The subspecific status of E. v. roborowskii is still 13 geographically distant localities in Iran and Central controversial, although Szczerbak (1975) confirmed Asia. Their results contradicted previous systematic its status according to color, pattern and characters hypotheses; revealed surprising relationships between of pholidosis. Boulenger (1921) suggested that the Iranian and Central Asiaian lineages and uncovered novel, morphological variation in the populations of E. v. cryptic evolutionary lineages (i.e. new putative species). roborowskii is not sufficient to support its subspecies Moreover, they argued that the eastern and southern status. The validity of this subspecies has not been Kazakhstan populations correspond to the traditional E. recognized for a long time (Mertens and Wermuth, 1960). v. roborowskii. However, Rastegar-Pouyani et al. (2012), More recently, on the basis of multivariate morphological who used most samples already analyzed by Rastegar- 26 27 28 8 11 20 29 10 15 18 22 21 9 13 16 19 30 14 17 7 12 25 23 24 4 3 6 5 1 2 E. v. caucasiaE. v. velox E. v. borkini E. v. roborowskii Figure 1 Entire distribution range of Eremias velox complex showing traditional subspecies’ range with different background color, and the sampling localities for different populations (numerical labels 14–30 with green dots), white dots with numbers 1–13 representing those from Rastegar-Pouyani et al.(2012). The locality number corresponds with that in Appendix A. 14 Asian Herpetological Research Vol. 5 E. v. roborowskii E. SE. C. kaza. E (8, 10–13) 1.0 E. v. velox 1.0 S. Aral Sea 1.0 D 1.0 Uzeb.(7) E. v. caucasia W. kaza. (9) 0.84 1.0 NW Khorasan, Iran(4) 1.0 1.0 C W Khorasan, Iran (5) Eremias sp. 3 1.0 1.0 1.0 SE Tehran, Iran (2) E. velox complex 1.0 SE Golestan, Iran (3) 1.0 B Eremias sp. 2 1.0 0.94 1.0 CN Khorasan, Iran (6) A 1.0 N Iran (1) Eremias sp. 1 Eremias strauchi Ophisops elegans Figure 2 Rastegar-Pouyani et al.’s (2012) phylogenetic hypothesis for populations of the Eremias velox complex from Iranian Plateau and Central Asia using partitioned Bayesian analyses of mtDNA data. A, B, C, D and E indicate the major clades. Values beside the node represent Bayesian posterior probabilities. Pouyani (2009), were unable to sample adequately the rRNA segment to gain a more comprehensive view on eastern part of the taxon’s range. There was no sample phylogeographic patterns in E. velox complex. This study from China included in their work. In addition, Rastegar- VSHFL¿FDOO\DLPVWR UHHYDOXDWHWKHSK\ORJHRJUDSKLF Pouyani et al. (2012) speculated that E. v roborowskii structure of E. velox complex, (2) test the phylogenetic occurs in western China, eastern Kazakhstan and Eastern affinities of the rapid racerunner populations in China, Uzbekistan. This inappropriate interpretation may give DQG WHVWWKHYDOLGLW\RIWKHVXEVSHFL¿FVWDWXVRIE. v. confusing clues about the identity of this subspecies, roborowskii. The hypothesis that E. v. roborowskii is valid resulting in incorrect inference of its phylogenetic particularly predicts that it will correspond with distinct, placement. It appears likely that the inclusion of more well-supported, and moderately divergent mtDNA rapid racerunner samples may get a better illustration of haplotype clade. their phylogeographic structure, and may also provide valuable information for their taxonomy. 2. Materials and Methods Thus, as an extension of the molecular phylogenetics of the rapid racerunner, an effort has been made to collect 2.1 Taxon sampling We collected a total of 87 samples some specimens from northwestern China and Russia. representing natural