This species can be found in many places in the Luoxiao mountain range between Hunan and Jiangxi. But populations could be shrinking due to the disappearance of streams and deforestation. Local people occasionally put salamanders in liquors, thinking that it promotes health.
Morphologically similar to Pachytriton brevipes, but different from the latter species in having short straight epibranchial bones (Shen et al., 2008). In both P. brevipes and P. labiatus, epibranchial bones are curved and elongated. Snout length shorter than interocular space, instead of longer as in P. brevipes or longer than or equal to interocular space as in P. labiatus. Head longer than wide. Cloacal area in male does not swell in breeding season; cloacal papillae are longer than in the other two species. Shen et al. (2008) state that P. archospotus further differs from P. brevipes in skull characteristics, possessing a frontosquamosal arch. But the frontosquamosal arch is also observed in some P. brevipes populations (Wu, Y. pers. comm.).
Mitochondrial and nuclear DNA data are available in Wu et al. (2010).
Summarized from Shen et al. (2008). A relatively large salamander. Body stout with smooth skin. Head fat and slightly flattened. Snout blunt. Eyes small. Labial fold prominent. Gular fold present. Osteological features include the presence of frontosquamosal arch and short straight epibranchial bones. Vertebral ridge absent. When limbs are adpressed, digits do not meet. Tail strong and laterally compressed at the posterior half. Dorsal caudal fin starts from the base of tail, and ventral caudal fin only visible at the end of tail. Dorsal color in life is blackish brown to lighter brown, and color can change slowly. Ventral color is bright orange to pale yellow with dark blotches. Small rounded black spots scattered around the body; some individuals have few or no black spots.
All measurements are from Shen et al. (2008).
Male (9 specimens). Total length: 143.9–184.6 mm; snout-vent length: 75.2–95.5 mm; head length: 22.4–26.2 mm; head width: 17.8–22 mm; forelimb length: 19.4–23.7 mm; hind-limb length: 20.7–28.8 mm.
Female (14 specimens). Total length: 161.1–211 mm; snout-vent length: 84.8–109 mm; head length: 22.4–28.4 mm; head width: 18.5–22.5 mm; forelimb length: 20.2–23.9 mm; hind-limb length: 22.8–30.2 mm.
Phylogeny based on mitochondrial DNA sequences suggests that Pachytriton archospotus is the sister species to P. brevipes with strong support (Wu et al., 2010).
The range of this species was until recently considered as part of the distribution range of Pachytriton brevipes (Fei et al., 2006). All Pachytriton populations occurring in the Luoxiao mountain range (southeastern Hunan, southwestern Jiangxi and northern Guangdong) are probably P. archospotus.
This species lives in mountain streams, ranging from 1,000m-1,600 m. In Mount Jing Gang it also occurs at approximately 800 m. The streams are surrounded by bushes and grassland and by broad-leaved evergreen and coniferous forest.
In May is the climax of the reproductive period. Long term observation by Shen et al. (2008) suggests that two and three year old individuals do not yet reproduce.