Unmasking Pachytriton labiatus (Amphibia: Urodela: Title Salamandridae), with Description of a New Species of Pachytriton from Guangxi, China Nishikawa, Kanto; Jiang, Jian-Ping; Matsui, Masafumi; Mo, Author(s) Yun-Ming Citation Zoological Science (2011), 28(6): 453-461 Issue Date 2011-06 URL http://hdl.handle.net/2433/216896 Right © 2011 Zoological Society of Japan Type Journal Article Textversion publisher Kyoto University ZOOLOGICAL SCIENCE 28: 453–461 (2011) ¤ 2011 Zoological Society of Japan Unmasking Pachytriton labiatus (Amphibia: Urodela: Salamandridae), with Description of a New Species of Pachytriton from Guangxi, China Kanto Nishikawa1*, Jian-Ping Jiang2, Masafumi Matsui1 and Yun-Ming Mo3 1Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan 2Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China 3Natural History Museum of Guangxi, Nanning 530012, China Examination of the lectotype and paralectotypes of Pachytriton labiatus (Unterstein, 1930) from southern China revealed that the specimens do not represent a member of Pachytriton, but are identical with a newt of another genus, Paramesotriton ermizhaoi Wu et al., 2009 also described from southern China. We suggest that Pac. labiatus should be transferred to Paramesotriton as a senior synonym of Par. ermizhaoi. We compared the morphology of the northeastern and south- western groups of newts previously called Pac. “labiatus,” with special reference to age and sexual variations. As a result, we confirmed that the two groups are differentiated sufficiently to be treated as different species. In this report, we revive the name Pac. granulosus Chang, 1933 to refer to the northeastern group of Pac. “labiatus”, and at the same time, describe a new species representing the southwestern group. Key words: Pachytriton labiatus, Paramesotriton, synonym, new species, China group), which are differentiated by a large genetic distance INTRODUCTION (calculated from mitochondrial and nuclear genes) compara- Pachytriton labiatus (Unterstein, 1930) is one of the ble to interspecific levels in Pachytriton and other newt gen- most popular species among Chinese salamandrids, era. Wu et al. (2010), thus concluded that the two groups because it has been traded as pets to many countries. are sufficiently differentiated to be treated as different spe- Although morphological variation and breeding behavior in cies, and proposed to restrict Pac. labiatus sensu stricto to captivity of the species have been reported (e.g., Thiesmeier the SW group, as the type locality of the species is included and Hornberg, 1997; Scholtz, 1998; Sparreboom and in the area of distribution of the SW group. Thiesmeier, 1998), its biology in natural habitats is still For the NE group of Pac. “labiatus” sensu Wu et al. poorly known. (2010), the name Pac. granulosus Chang, 1933 had been Unterstein (1930) described this species on the basis of available (for taxonomic history of Pac. granulosus, see one male and three females from “Yaoshan, Kwangsi, China” Nishikawa et al., 2009). However, Hou et al. (2009) revived (Mt. Dayao, Guangxi Zhuang Autonomous Region, China). the name as different genus Pingia granulosa. They consid- All of the type specimens are stored in the Museum of Natural ered that Pin. granulosa is a terrestrial newt, which is differ- History, Humboldt University Berlin (ZMB). Unterstein (1930) ent from the sympatric and aquatic Pac. “labiatus”. provided measurement data on a subadult (halbwüchsiges) However, Nishikawa et al. (2009) soon showed that Pin. specimen, but did not indicate the register number of the granulosa is the immature terrestrial morph of Pac. specimen. Much later, Bauer et al. (1993) examined the syn- granulosus, which becomes aquatic after maturation. Wu et types and designated the lectotype and paralectotypes. al. (2010) seems to have followed Hou et al. (2009) and con- However, no one has compared these type specimens with sidered that the NE group of Pac. “labiatus” had no avail- topotypic specimens to date. able name. They, thus, tentatively retained the name Pac. Recently, Wu et al. (2010) reported that the newt then labiatus for the NE group, noting that the group was so dif- called Pac. “labiatus” is morphologically separated into two ferentiated in body coloration and genetic distance as to be geographically isolated groups, “northeastern P. labiatus” separated into different taxa. However, as pointed out by (hereafter, NE group) and “southwestern P. labiatus” (SW Nishikawa et al. (2009), the NE group should be treated as Pac. granulosus. * Corresponding author. Phone: +81-75-753-6848; In this paper, we examine the type specimens of Pac. Fax : +81-75-753-2891; E-mail: [email protected] labiatus and compare them with topotypic specimens of this Supplemental material for this article is available online. species to solve the taxonomic confusion noted above. doi:10.2108/zsj.28.453 454 K. Nishikawa et al. characters directly. MATERIALS AND METHODS Survey on the type specimens of Pac. labiatus Morphological variation in Pac. “labiatus” We examined all of the four type specimens of Pac. labiatus: In order to assess taxonomic relationships of populations of the lectotype (ZMB 34087) and three paralectotypes (ZMB 34088, Pac. “labiatus”, we compared a total of 10 characters noted above, 50280, and 50281). For comparison, we examined 35 topotypic and ratio values of eight characters to SVL. We compared differ- Pac. “labiatus” (12 males, 17 females, and six juveniles) and 14 ences in these characters between each topotypic specimen of 1) Par. ermizhaoi (three males, four females, and seven juveniles) in Pac. “labiatus” from a population in Mt. Dayao, Jinxiu (hereafter, the collection of the Chengdu Institute of Biology (CIB). The speci- JINXIU) that belongs to the SW group sensu Wu et al. (2010), rep- mens of Par. ermizhaoi had been catalogued as Pac. labiatus or resented by 12 males, 17 females, and six juveniles; and 2) Pac. Par. chinensis (Gray, 1859) in the CIB collection, but had charac- granulosus from a population in Tiantai, Zhejiang (hereafter, teristics that match well with the original description of Par. TIANTAI), the NE group sensu Wu et al. (2010), nine males, 11 ermizhaoi (Wu et al., 2009): epibranchial nearly straight, maxilla females, and three juveniles (Fig. 1). oriented angular to the body axis, and skin slightly wrinkled or Recently, Hou et al. (2009) designated the neotype of Pingia smooth without distinct dorsal ridge. By contrast, the topotypic Pac. granulosa (= Pac. granulosus whose holotype seemed to be lost in “labiatus” has epibranchials wrapping the neck dorsolaterally, the WWII: see Nishikawa et al., 2009) collected from a locality ca. 200 km maxilla connected with the pterygoid, and smooth skin without a northeast of the type locality (Mt. Longwang, Zhejiang Province). dorsal ridge. Paramesotriton chinensis has similar skull character- The neotype seems to be a juvenile and, more problematically, a istics with Par. ermizhaoi, but has more roughened skin than Par. terrestrial morph, which is rarely encountered and shows morphol- ermizhaoi, with distinct dorsal and dorsolateral ridges. We analyzed ogy quite different from adults, which are much easier to find complete sequences of mitochondrial cytochrome b gene (1141 bp) (Nishikawa et al., 2009). Thus, the neotype is not practically suitable of two of the seven topotypic juveniles examined morphologically for comparison with adult specimens, and Nishikawa et al. (2009) (CIB GX20070763: GenBank accession no. AB601425, CIB could not find any difference between the neotype and specimens GX20070764: AB601426) and compared them with those of the from the type locality (although only juveniles were compared). holotype and a paratype of Par. ermizhaoi (CIB 88141: GQ303670, Because of this situation, we used available adult samples from the CIB 88140: GQ303671 [Wu et al., 2009]). These four sequences type locality of Pac. granulosus (TIANTAI) as representing the NE differed from each other by at most 0.17% in uncorrected P- group. distance. Thus the juveniles were confirmed as Par. ermizhaoi. Differences in metric (mm) and meristic (ratio) values of adults Except for a Par. ermizhaoi (CIB 21146) collected from unknown were statistically tested between the two populations (JINXIU and locality in Guangxi, all the type specimens and the specimens we TIANTAI) by Student’s t-test and Mann-Whitney’s U test, respec- examined were collected from the type locality of Pac. labiatus and tively. The significance level was assumed as 95% in all these sta- Par. ermizhaoi, Mt. Dayao. tistical tests. The following measurements were taken for comparison: TOL RESULTS (total length): tip of snout to tip of tail; SVL (snout-vent length): tip of snout to anterior tip of vent; MXHW (maximum head width): mea- Notes on types of Pac. labiatus sured at widest point; ENL (eye-nostril length): external nare to The type specimens of Pac. labiatus were in good con- anterior tip of upper eyelid; IND (internarial distance): minimum dis- dition (Table 1, Fig. 2A–D). The measurements (in mm) of tance between external nares; AGD (axilla-groin distance): mini- the lectotype were nearly identical to those shown in the mum distance between axilla and groin; TAL (tail length): anterior tip of vent to tail tip; VL (vent length): anterior tip to posterior tip of vent; MXTAH (maximum tail height): tail height measured at highest point; FLL (forelimb length): distance from axilla to tip of longest fin- ger; HLL (hindlimb length): distance from groin to tip of longest toe. Wu et al. (2009) followed Stuart and Papenfuss (2002) in the measurements and took “TAL” from posterior (anterior in our case) tip of vent to tip of tail, without showing vent length (VL). We thus used values of TAL–VL instead of TAL, in comparing our data with those given by Wu et al. (2009). All measurements were taken to the nearest 0.1 mm with a dial caliper. We used a stereoscopic binocular microscope when necessary. The sex and maturity of the specimens were checked by slight dissections.