Paramesotriton aurantius, Yuan, Zhiyong, Wu, Yunke, Zhou, Jiajun & Che, Jing, 2016

Yuan, Zhiyong, Wu, Yunke, Zhou, Jiajun & Che, Jing, 2016, A new species of the genus Paramesotriton (Caudata: Salamandridae) from Fujian, southeastern China, Zootaxa 4205 (6), pp. 549-563 : 556-561

publication ID	https://doi.org/ 10.11646/zootaxa.4205.6.3
publication LSID	lsid:zoobank.org:pub:D7A88CFD-D21F-474E-9115-412EA82A9BE9
DOI	https://doi.org/10.5281/zenodo.5616309
persistent identifier	https://treatment.plazi.org/id/03C9B004-FFAF-F26C-FF35-FAF89097BDF2
treatment provided by	Plazi
scientific name	Paramesotriton aurantius
status	sp. nov.

Treatment

Paramesotriton aurantius View in CoL sp. nov.

( Fig. 3–10 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 )

Holotype. KIZ 026210 View Materials ( Fig. 5 View FIGURE 5 ), an adult male from Jiulongjin, Zherong , Fujian Province, 27.20 °N, 119.99 °E, elevation 832 m, collected by Jiajun Zhou on November 27, 2015. GoogleMaps

Paratypes. KIZ026208, 0 26209, 0 26211 (males), collected at the same time and locality as the holotype. KIZ 012817 –21 (females), 012822 –25 (males), 012877 – 78 (males), from Feiluan, Luoyuan country, Fujian Province, 26.54 °N, 119.67 °E, elevation 590 m, collected by Zhiyong Yuan on July 19, 2011 GoogleMaps . KIZ 012879 –83 (males), 012884 - 87 (females), 27.25 °N, 119.94 °E, elevation 814 m, near Longxi reservoir, Zherong, Fujian Province, collected by Zhiyong Yuan on July 22, 2011 GoogleMaps . KIZ 013535–36 View Materials (females), 013537–43 (males), 013544–45 (females), near Dongzheng reservoir, Putian , Fujian Province, collected by Zhiyong Yuan on Novermber, 2012.

Diagnosis. The species is allocated to the genus Paramesotriton based on its rough skin, presence of a glandular ridge on the side of its head, orange spots and blotches present on the ventral surface, and its placement in the molecular phylogeny( Fei et al. 2006; Yuan et al. 2014).

The new species differs from all members of the P. caudopunctatus group ( P. caudopunctatus , P. wulingensis , P. zhijinensis , P. longliensis and P. maolanensis ) by a combination of the following characters: (1) absence of broad irregular yellow stripes on dorsolateral ridge and the lateral of tail (vs. presence in P. caudopunctatus , P. wulingensis , P. zhijinensis and P. longliensis ); (2) absence of colored spots on the tails of males (vs. presence in P.

caudopunctatus ); (3) absence of vestigial gills and gill filaments in adults (vs. presence in P. zhijinensis ); (4) rough skin and normal development of the eyes (vs. smooth kin and reduced eyes in P. maolanensis ).

Within the P. chinensis group, P. aurantius sp. nov. differs from P. labiatus by having very rough skin and evident vertebral ridge (vs. smooth kin and inconspicuous vertebral ridge in P. labiatus ). It is distinguishable from P. guangxiensis , P. deloustali , P. fuzhongensis , and P. yunwuensis by having numerous small irregular orange-red or yellow spots on the chin, venter, underside of axillae, and cloaca (the latter four species have large oranges ventral blotches). The new species differs from P. qixilingensis by having an orange and continuous vertebral ridge (vs. intermittent vertebral ridge with dark brown color), developed tail fins expanding posteriorly (vs. relatively underdevelopment of tail fins). Furthermore, it differs from P. chinensis by having a small groove at the base of vomerine tooth series ( Fig. 6 View FIGURE 6 B, C) (vs. absence), fewer warts on each side of vertebral ridge (vs. more, distinct warts). Additionally, Paramesontriton aurantius sp. nov. differs from P. hongkongensis by having rough skin (vs. smooth), presence of an orange vertebral ridge (vs. absence), and presence of irregular yellow spots on cheek, lateral sides of dorsum, lateral sides of tail, base of limbs (vs. absence).

Description of the holotype. Adult male in excellent state of preservation. SVL 66.8 mm, TAL 56.3 mm, for further measurements see Tables 2 View TABLE 2 and 3 View TABLE 3 . Body relatively slender; head longer than wide (length/width = 1.38); head wider than neck and body; snout truncate in dorsal and lateral view; nostrils short, close to snout tip, rounded in dorsal profile; eyes small, located at the upper corner of mouth, not bulging above dorsal surface of cranium, only visible in lateral view; glandular ridge on each side of the head, gradually enlarge from the posterior margin of snout to neck in dorsal view; one “V” parietal ridge present, indistinct; labial fold present; gular fold well developed; tongue short, ovoid, attach to mouth floor with free lateral margins ( Fig. 6 View FIGURE 6 A); vomerine tooth series as single distinct Ʌ-shaped with small groove at base, at middle of each choana ( Fig. 6 View FIGURE 6 B). Vertebral ridge brown, conspicuous, unintermittent, from occiput to tail. Forelimbs long, reach beyond tip of snout when adpressed forward; palm and sole overlap when adpressed forelimb backwards and hind limb forward along body flank; without metacarpal and metatarsal tubercle; four fingers and five toes without webbing ( Fig. 7 View FIGURE 7 ); slightly developed velum present in the third toe; relative finger length 1 <4 <2 <3; relative toe length 1 <5 <2 <4 <3. Tail long (SVL/ TAL = 1.19); dorsal and ventral caudal fin evident, expanding on posterior half of tail; tail-tip rounded. Cloaca large slit, swollen, villous mastoid around cloaca, many pubes on gaps of cloaca. Skin rough, many warts and granular glands on dorsal skin and lateral sides of tail; ventral skin wrinkled, with small warts.

In life, dorsal and lateral color of head, body, limbs, and tail dark brown. Ventral color of head, body and limbs beige, slightly lighter than dorsal and lateral surfaces. Single orange-red stripe from the posterior margin of cloaca to the first half part of tail on ventral side. Irregular yellow spots or orange blotches on most parts of the body, including cheek, flanks, lateral sides of tail, base of limbs, chin, venter, underside of the four limbs, and cloaca. Distinct white band extends laterally from the base of tail to the tail-tip. Finger and toe tips pale yellow. In preservation, the orange, orange-red colorations fade to yellow ( Fig. 5 View FIGURE 5 ).

Morphological Variation. Morphometric measurements of the holotype and paratypes are summarized in Tables 2 View TABLE 2 and 3 View TABLE 3 . In addition to morphometric variations among individuals, the following variations are also observed: (1) the dorsal color varies between the specimens collected from streams (brown with irregular yellow spots) and specimens collected on the land (black with irregular yellow spots) ( Figs. 3 View FIGURE 3 , 4 View FIGURE 4 ); (2) the number, shape and position of ventral orange-red spots varies among individuals; (3) cloacae are larger and more swollen in males than that in females ( Fig. 8 View FIGURE 8 ); (4) the length and width of tail are sexually dimorphic, with tails of males proportionally shorter and wider than females mostly (TAL/SVL 0.96–1.24 in males, 0.90–1.03 in females); (5) the bluish-white caudal stripes on the posterior half of tails are observed in several males collected from the streams (KIZ026208, KIZ026209, KIZ026211) but not in males collected from the roadside drainages or from the land ( Figs. 3–4 View FIGURE 3 View FIGURE 4 ).

Etymology. The specific epithet is derived from aurantium L. for orange colored, in reference to the orange coloration on the vertebral ridge of the new species.

Natural history. Habitats of the three populations are distinct. In Zherong, brown colored individuals were found in flat and slow moving streams with sand, leaves, fine gravel, and scattered large rocks ( Fig. 9 View FIGURE 9 A). The width of the stream is about 3–5 m, and most parts of the stream are shallow, except for few deep pools scattered along the stream, which vary between 1 to 2 m in depth. Both sides of the stream are dominated by moist evergreen forest. During the survey period for the streams in Feiluan, males were encountered much more often than females (observed sex ratio 18:1). All males from the streams had a bluish-white lateral caudal stripe. We also found black colored individuals from a storm drain along a road ( Fig. 9 View FIGURE 9 C, D) near the stream at dawn, and in these individuals the bluish-white lateral caudal stripe was absent in males ( Fig. 3 View FIGURE 3 ). Very small eggs were evident after dissecting the females from the storm drain. The storm drain had shallow water and all the newts from the storm drain went back to the forest after sunrise. Although the habitat in Dongzheng is overall similar to the type locality, the stream is located at the edge of the forest instead of passing through the forest. In Feiluan, however, dense bushes were present along the stream bank instead of evergreen forests as for the type locality ( Fig. 9 View FIGURE 9 B).

When threatened out of water (e.g. being captured), individuals of the new species often produced pungent and white secretions from the skin. Many individuals also feigned death by adpressing their limbs against their bodies and remaining stationary ( Fig. 10 View FIGURE 10 ).

Distribution. The species is known from Fujian Province, southeastern China. Aside from the localities provided here, it is possible that a documented population of P. chinensis from Wuyishan in northern Fujian also belong to this new species ( Fei et al. 2006; 2012). Our discovery not only fills the distributional gap of the genus in southeastern China but highlights the cryptic species diversity in these poorly-surveyed, yet heavily-populated areas. Further taxonomic studies with additional samples from different localities both within Fujian Province and among other adjacent provinces are needed to verify the actual distribution range of the species.