Paramesotriton ermizhaoi, Wu, Yunke, Rovito, Sean M., Papenfuss, Theodore J. & Hanken, James, 2009

Wu, Yunke, Rovito, Sean M., Papenfuss, Theodore J. & Hanken, James, 2009, A new species of the genus Paramesotriton (Caudata: Salamandridae) from Guangxi Zhuang Autonomous Region, southern China, Zootaxa 2060, pp. 59-68 : 64-66

Paramesotriton ermizhaoi species nov.

( Fig. 3 ABC)

Holotype: CIB 88141, an adult male collected in Mt. Dayao (24°07´N, 110°13´E, 881m elevation), Jinxiu Yao Autonomous County, Guangxi Zhuang Autonomous Region, P. R. China; collected by Jiatang Li on July 7, 2006.

Paratypes: Same locality as holotype: CIB 88140, CIB 95998-96000, collected with the holotype on the same date; MVZ 230616 - 230621, collected by E. Zhao in March 1999.

Diagnosis: Paramesotriton ermizhaoi is assigned to the genus Paramesotriton because of its slender and nearly straight epibranchial bones, maxillary bones oriented angular to the body axis, and laterally compressed tail. This species can be diagnosed from other congeners by the following combination of characters: skin relatively smooth; granular warts absent on head and body; vertebral ridge not prominent; head depressed and nearly flat in profile; habitus slender and depressed; limbs short—when adpressed against flank, fingers and toes hardly meet; dorsum olive brown with irregular black flecks; ventral orange-red blotches irregular in shape.

Description of the holotype: A slender and flat newt, preserved with mouth open. Head oval in shape, depressed and nearly flat in profile. Snout truncate and slightly projecting beyond lower mandible. Nostrils close to snout tip. Labial fold evident throughout posterior half of upper jaw. Skull relatively narrow, with maxillary bones oriented angular to body axis. Maxillary tips lie anterior and lateral to pterygoid bones; no contact between maxillary and pterygoid. Fronto-squamosal arch complete but not very robust. Epibranchial bones slender, nearly straight, only slightly flared dorsally. Vomerine tooth patch Λ-shaped, tooth rows converging anteriorly and exceeding the anterior limit of choanae. Tongue adhering to mouth floor with free lateral margins. Parotoid region evident, but not enlarged. Gill filaments absent. Gular fold present. Skin relatively smooth on head and body, with small transverse wrinkles. Vertebral ridge thin, slightly elevated. Lateral dorsal ridge absent. Thirteen trunk vertebrae. Four fingers, five toes, without webbing. Tail laterally compressed; posterior dorsal caudal fin evident, ventral caudal fin indistinct; tail extremity round in profile. Cloaca swollen, with a few papillae near posterior limit.

Color of holotype in life: Dorsum olive brown with irregular black flecks. Vertebral ridge with orange tint. Venter paler brown. Irregular orange-red blotches on venter and anterior portion of cloaca with indistinct black margin; some blotches connected into short irregular stripes. Orange-red on underside of tail.

In preservative, dorsum and venter black. Vertebral ridge inconspicuous. Ventral bright orange fading to yellow to milky white; black margins invisible.

Variation: Morphology of paratypes resembles that of holotype except that females have smaller and nonswollen cloaca without papillae. Linear measurements are summarized in Table 2. Color of ventral blotches ranges from orange to red, spreading to chin and underside of axillae, varying in shape and arrangement. Black marks border those blotches or intersperse on venter.

Holotype Females (N = 6) Males (N = 5)

Measurements (CIB 88141) Range Mean ± SE Range Mean ± SE SVL 63.5 46.6–66.8 56.3 ± 2.7 46.4–63.5 56.1 ± 3.1 TTL 126.0 94.0–137.5 112.8 ± 5.9 92.2–127.6 111.5 ± 6.8 TAL 57.7 44.7–65.5 53.4 ± 3.0 43.3–60.2 51.1 ± 3.3 TAD 7.5 5.5–8.1 7.0 ± 0.4 5.5–8.5 7.3 ± 0.5 HL 17.7 14.4–17.4 15.9 ± 0.5 14.8–17.8 16.1 ± 0.7 HW 12.1 8.8–12.6 10.7 ± 0.5 9.1–12.3 10.9 ± 0.6 IO 7.1 5.3–6.9 6.0 ± 0.2 5.4–7.1 6.4 ± 0.3 EN 4.9 3.2–4.2 3.8 ± 0.2 3.1–4.9 4.0 ± 0.3 IN 3.7 2.7–3.6 3.1 ± 0.1 2.4–3.7 3.1 ± 0.2 AX 31.3 20.2–36.7 27.7 ± 2.2 21.4–31.3 27.6 ± 1.7 AL 15.6 12.6–15.4 13.8 ± 0.4 12.5–17.4 14.6 ± 0.9 PL 16.0 13.1–15.6 14.2 ± 0.4 13.5–17.4 15.2 ± 0.7 Etymology: The new species is named after Ermi Zhao, a prominent Chinese herpetologist and educator, for his great contribution to the development of herpetological study and the training of a new generation of scientists in China.

Habitat: Stream in broadleaf forest with herbaceous plants and vines. Stream is 3-4 meters wide and shallow, flowing slowly in a valley ( Fig. 3 C). Substrates include gravels, scattered small rocks, and semisubmerged larger rocks. Along the stream are pools with a very slow current. Newts are found at the stream bottom, usually under rocks or between crevices during daytime. Fishes and small aquatic invertebrates coexist with Paramesotriton ermizhaoi , and Pachytriton labiatus is found in the same stream drainage at a higher elevation.

Discussion: Paramesotriton ermizhaoi is unusual insofar as a large portion of individuals possess 13 trunk vertebrae; other congeneric species normally have 12 trunk vertebrae ( Chan et al. 2001). Although variation has been observed in other Paramesotriton , it is rare. However, six of eleven P. ermizhaoi (including the holotype) have 13 trunk vertebrae ( Fig. 4 ); the other five specimens have 12. The number of trunk vertebrae does not appear to be correlated with gender. A similar situation occurs in the European salamandrid Ommatotriton ophryticus , in which the modal number of trunk vertebrae varies from 12 to 13 in different geographic populations ( Litvinchuk et al. 2005). Orska and Imiolek (1962) reported the correspondence of vertebral number to developmental temperature in salamanders. Future research is necessary to evaluate the correlation between environmental temperature and embryonic development in P. ermizhaoi .

Paramesotriton ermizhaoi may have been long misidentified as another Asian salamandrid species. Scholz (1998) reported a potentially new species of Pachytriton from the pet trade, named Pachytriton C. In fact, most descriptions of morphology, coloration, and behavior of Pachytriton C match with P. e r m i z h a o i. Due to lack of molecular data and known locality, Scholz (1998) did not make a definitive taxonomic statement on Pachytriton C. We suspect that the two names refer to the same species.

The only known locality of P. ermizhaoi, Mt. Dayao , is located within the putative Guangxi population of P. c h i n e n s i s ( Fei et al. 1999; Zhang & Wen 2000; Fei et al. 2006), which was first described in rivers at inland from Ningbo, Zhejiang Province ( Gray 1859). However, P. ermizhaoi has been identified mistakenly as P. chinensis despite their different morphologies. For instance, the paratypes of P. e r m i z h a o i from MVZ were originally catalogued as P. c h i n e n s i s. We also note that the P. chinensis used by Lu et al. (2004) from Mt. Dayao actually are P. ermizhaoi , based on mitochondrial sequences. To our knowledge, no true P. c h i n e n s i s has been collected from Mt. Dayao. It is possible that claims of a disjunct Guangxi population of P. chinensis are incorrect due to misidentification. However, Zhang and Wen (2000) provide an account on Guangxi P. chinensis that matches the diagnostic characters of this species. More fieldwork is needed to determine if P. chinensis occurs in Guangxi Zhuang Autonomous Region.

Comparative material examined: P. caudopunctatus ( MVZ 236250-236254 from Guizhou, China), P. chinensis ( MVZ 230360, CIB 95899, CIB 95907-95911 from Zhejiang, China), P. fuzhongensis ( MVZ 230622 - 230625 from Guangxi Zhuang Autonomous Region, China), P. hongkongensis ( MVZ 230365 - 230370 from Hong Kong, China), P. deloustali ( MVZ 222122-222123, MVZ 223627-223629 from Tam Dao, Vietnam), P. laoensis ( FMNH 255450, FMNH 257850, FMNH 257852, FMNH 257853 from Xiang Khouang, Laos).

Figures

FIGURE 4. Radiograph of P. ermizhaoi (CIB 88141, holotype: 3). Arrow points to the 13 th trunk vertebrae.

FIGURE 3. A: Dorsal view of living P. ermizhaoi (CIB 95998, paratype: Ƥ); B: Ventral view of living P. ermizhaoi (CIB 88141, holotype: 3). C: habitat of P. ermizhaoi in Mt. Dayao, Jinxiu Yao Autonomous County, Guangxi Zhuang Autonomous Region, China.