Paramesotriton guangxiensis (Huang, Tang and Tang, 1983)
Guangxi Warty Newt (English), Guangxi Salamander
Due to its vulnerable habitat and the limited extent of its presently known occurrence this species is listed as endangered (IUCN, 2010). The major threat is habitat loss and degradation due to agriculture. Population trend is decreasing.
Paramesotriton guangxiensis is similar to P. chinensis, notably by its granular skin, but it differs from the latter species by having a flatter body, entirely dark-brown color of the back, short forelimbs, prominent dorsal ridge, and high, compressed tail (Huang et al., 1983).
The mitochondrial DNA sequence data are available in Wu et al. (2010).
Morphologically, Paramesotriton guangxiensis resembles but is nevertheless distinct from P. deloustali, P. yunwuensis and P. fuzhongensis. In P. guangxiensis and P. yunwuensis the extended forelimb does not reach the posterior margin of the eye. In P. deloustali the extended forelimb reaches the midpoint of the eye and in P. fuzhongensis it reaches even further anteriorly to a point midway between the eye and the nostril. Compared to P. yunwuensis, P. guangxiensis is smaller, more gracile (e.g., the trunk is relatively flat in cross-section, versus square or round in P. yunwuensis), and its tail is shorter and deeper.
Moderately small-sized warty newt. Flat, triangular head, longer than wide. Flat and stout body. Snout truncated. Labial fold well developed. Forelimb merely reaches the eye when stretched forward. Digits just meet when forelimbs and hind limbs are adpressed. Skin rugose with small wrinkles, high vertebral ridge extending onto the tail. Warts densely present around neck and dorsum. Tail length shorter than snout-vent length, ending in a thin tip. Cloaca swollen with papillae in the male during reproductive season. Color of upper side dark brown; underside black with large, irregular yellow to orange blotches. Lower tail fin orange, fading towards the tip. Color is lighter in female.
All measurements are from Huang et al. (1983).
Male (9 specimens). Total length: 124.8–139.5 mm; snout-vent length: 67.8–75.5 mm; head length: 20–22.8 mm; head width: 15–17.2 mm; forelimb length: 19.3–23.1 mm; hind-limb length: 19.2–23 mm.
Female (1 specimens). Total length: 134.2 mm; snout-vent length: 71 mm; head length: 21.2 mm; head width: 16.1 mm; forelimb length: 21 mm; hind-limb length: 19.9 mm.
Ecology and Distribution
It is only known from the type locality, Paiyang shan, Ningming County in Guangxi, China, where it occurs at 470 m altitude (Huang et al., 1983; Zhang & Wen, 2000).
Paramesotriton guangxiensis occurs in low gradient streams around elevations of 500 m. The stream is 1–1.5 m wide, 0.3–0.8 m deep (Pang et al., 1991). Water is clear and slow and full of small rocks and sand. Dense forest and bushes cover the stream. Newts hide under rocks in the stream or in grasses near the stream edge. It is often found on land (0.5–1 m away from the stream) after heavy rains (Fei et al., 2006). This species is mostly nocturnal and preys on small insects and earthworms.
Evolution and Systematics
The large head and color pattern give the species the look of a small-sized P. deloustali. Pang et al. (1991) synonymized P. guangxiensis with P. deloustali based on morphological characters. However, mitochondrial phylogeny suggests that P. guangxiensis is more closely related to P. yunwuensis and P. fuzhongensis than to P. deloustali (Wu et al., 2010). Those four species can be distinguished from each other under close examination (see Look Alikes).
- Trituroides guanxiensis Huang, Tang, and Tang, 1983, Acta Herpetol. Sinica, Chengdu, N.S., 2 (2): 37. (synonym)
- Paramesotriton guangxiensis Zhang and Wen, 2000, Amph. Guangxi: 28. (synonym)
- Paramesotriton (Paramesotriton) guanxiensis Dubois and Raffaëlli, 2009, Alytes, 26: 49, 65. (synonym)