Pachytriton wuguanfui, Yuan & Zhang & Che, 2016

Yuan, Zhi-Yong, Zhang, Bao-Lin & Che, Jing, 2016, A new species of the genus Pachytriton (Caudata: Salamandridae) from Hunan and Guangxi, southeastern China, Zootaxa 4085 (2) : 227-230

Pachytriton wuguanfui sp. nov.

( Figs. 4–7 , Table 2)

Holotype. KIZ08758 ( Fig. 5 ), an adult female from Mt. Gupo, Hezhou city , Guangxi Zhuang Autonomous Region, China; 24.64° N, 111.53° E, elevation 1202 m, collected by Zhiyong Yuan on August 17, 2010.

Paratypes. KIZ 08755–08757 (three females), 0 8759 (male), collected at the same time and locality as the holotype. KIZ 021705 –06 (two females), 0 21708 (female), 0 21711 (female), 0 21712 (male), KIZ 021832 (female), 021833 –35 (three males) from Chahuaping, Dao country, Hunan province, 25.22° N, 111.79° E, elevation 649 m, collected by Zhiyong Yuan and Limin Ding on June 18, 2012.

Diagnosis. Pachytriton wuguanfui sp. nov. is assigned to the genus Pachytriton by its molecular phylogenetic position and the following morphological characters: head oval and flat; skin very smooth; labial folds obvious on upper jaw; limbs short; tips of fore- and hindlimbs widely separated when limbs adpressed against body flank; tail long, base broad; posterior half of tail gradually laterally compressed; dorsal caudal fin evident. This species can be differentiated from congeners by the following combination of morphological characters: dorsum uniformly dark brown without bright orange dots and black spots over the body; tips of fingers and toes orange on dorsal side; costal grooves between axilla and groin not discernable; Ʌ-shaped vomerine tooth series widely open.

Description of the holotype. This specimen is a moderately sized newt (TTL = 155.7 mm). Head oval and flat, much longer than wide (HL/HW = 1.24). Snout truncate, projects slightly beyond lower jaw. Nostril small, nearly to the tip of snout. Eyes small and do not protuberate in dorsal view. Labial fold well developed on upper jaw. Gular folds weak. Parotoid gland prominent and protuberant. Tongue pad elliptical, adheres to mouth floor. Vomerine tooth series Ʌ-shaped. Dorsal vertebral groove conspicuous along the dorsal midline. Skin smooth. Costal grooves between axilla and groin lacking. Limbs very short (AL/SVL = 0.18, PL/SVL = 0.21). The forelimb is slightly shorter than the hindlimb (AL/PL = 0.85); tips of forelimbs and hindlimbs are well separated when adpressed to body flank. Fingers and toes moderately webbed on the sides (so digits appear flat) and without palmar tubercles. The relative finger lengths are 1 <4 <2 <3 and relative toe lengths are 1 <5 <2 <4 <3, the fifth toes are very short. Dorsal caudal fin evident extends from tail-base to tail-tip. Ventral caudal fin prominent on posterior half of tail. Tail-tip rounded. Cloaca short slit, small and not protuberant.

Color in life. In life, dorsal color uniform dark brown; venter and chin brown and scattered with large, irregular, orange blotches; cloaca, underside of limbs and tail also orange. Tips of digits appear orange red when viewed from above.

Color in preservative. In preservation, dark brown coloration turns to grey black; orange coloration fades to milky white.

Variation. The cloaca in males is larger and more swollen than that in females, with papillae on the cloacal wall. Sexual dimorphism in body size could not be determined because only two well-preserved adult males. Ventral coloration varies greatly from a large amount of orange, irregular blotches (KIZ08756–08759, KIZ 021705 – 0 6, 0 21708, 0 21712, 0 21832, 0 21833, 021835) to only a few small orange spots (KIZ08755, 0 21711, 021834).

Etymology. The specific epithet wuguanfui is a patronym honouring Guanfu Wu (Chengdu Institute of Biology, Chinese Academy of Sciences), a prominent Chinese herpetologist and educator, for his great contribution to the taxonomy, karyology, and osteology of amphibians and reptiles in China.

Habitat and distribution. This species inhabits small montane streams in broadleaf forests. Streams inhabited by these newts are ca. 2 meters wide and 0.5–1 meters in depth; slope is steep, with fast flowing clean and cold water. Many large boulders are scattered in or around the streams. Stream substrates include gravels, scattered small rocks, leaves and sands. Frogs in the genera Megophrys , Amolops and Quasipaa were also found in these habitats. Newts were found along the stream at night. We did not encounter the species during the day. Pachytriton wuguanfui sp. nov. were found at Mt. Jiuwei in Hunan and Mt. Gupo in Guangxi and it likely occurs in nearby mountains between the distribution of P. inexpectatus in the west and P. xanthospilos in the east.

Comparisons. Pachytriton wuguanfui sp. nov. described here distinctly differs from P. archospotus , P. brevipes , and a few populations of P. granulosus by the lack of black spots on the whole body (vs. presence of black spots in these species). It differs from P. changi and P. xanthospilos by lacking orange dots on the dorsolateral side (vs. presence of orange spots or blotches that extend ribbon-like along the dorsolateral sides of the body in both species) and from P. moi by having orange blotches on venter (vs. lack of orange blotches on venter in P. moi). It differs from P. inexpectatus , P. granulosus and P. feii by lacking costal grooves between axilla and groin (vs. all these three species present costal grooves). The anterior end of the vomerine tooth series is also more widely open in the new species than P. inexpectatus ( Fig. 8 ). Finger and toe tips in life appear orange on the dorsal side in P. wuguanfui sp. nov., which distinguishes the new species from P. feii (digit tips appear black in life).

Figures

FIGURE 4. Dorsal (A) and ventral (B) views of living female Pachytriton wuguanfui sp. nov. (KIZ 08755).

FIGURE 5. Dorsal (A) and ventral (B) views of the holotype of Pachytriton wuguanfui sp. nov. (KIZ 08758) in preservation. The scale shows 20 mm.

FIGURE 6. Ventral views of (A) forelimb and (B) hindlimb of the holotype of Pachytriton wuguanfui sp. nov. (KIZ 08758) in preservation.

FIGURE 7. Habitat at the type locality of Pachytriton wuguanfui sp. nov., Mt. Gupo, Hezhou, Guangxi, China.

FIGURE 8. Vomerine tooth morphology in adult (A) Pachytriton wuguanfui sp. nov. (KIZ 021834) and (B) Pachytriton inexpectatus (KIZ 014508, Mt. Maoer, Guangxi). The scale shows 1.7 mm.