AmphibiaWeb - Pachytriton moi


(Translations may not be accurate.)

Pachytriton moi Nishikawa, Jiang & Matsui, 2011
Mo's Stout Newt; Pachytriton de Mo
family: Salamandridae
subfamily: Pleurodelinae
genus: Pachytriton
Species Description: Nishikawa K, Jiang J-P, Matsui M 2011 Two new species of Pachytriton from Anhui and Guangki, China (Amphibia: Urodela: Salamandridae). Current Herpetology 30:15-31.

© 2011 Kanto Nishikawa (1 of 1)

AmphibiaChina 中国两栖类.

Conservation Status (definitions)
IUCN Red List Status Account Endangered (EN)
National Status None
Regional Status None



View distribution map in BerkeleyMapper.

Pachytriton moi is a Chinese newt whose snout-vent length measures 100.2 mm. The species is described from one adult male and five juveniles. It has smooth skin and a robust, stout body with 10 costal grooves. It has a weak gular fold and no dorsolateral ridges. The head is a large, squared-off oval in shape, and flat when viewed in profile. The snout is long, truncate, and extends slightly past the lower jaw. Nostrils are close to the tip of the snout and a labial fold can be seen in the posterior half of the upper jaw. Vomerine teeth rows converge anteriorly into an inverted V shape and extend past the anterior limit of the choanae. It has a wide skull with a robust front-squamosal arch. There are 12 trunk vertebrae. One costal fold present between adpressed limbs. Fingers and toes lack webbing. Laterally compressed tail with posterior dorsal fin is present (Nishikawa et al. 2011).

Pachytriton moi can be distinguished from P. inexpectatus by its longer snout, larger body, and wider head. It also has the longest vomerine tooth series. Juveniles of P. moi also have a longer snout than P. inexpectatus and have more finely scattered ventral markings (Nishikawa et al. 2011).

In life, adults are uniformly dark brown on the dorsal side of the body and lighter brown with small orange spots on the ventral side. They are slightly light orange on the underside of the tail. Juveniles may have orange spots on dorsolateral regions and finely scattered orange or reddish-orange markings on the ventral side. In preservative, the dorsal brown fades to a lighter brown, and the orange ventral spots fade to a cream color (Nishikawa et al. 2011).

The species authority stated that the juveniles varied slightly from adults but did not specify how (Nishikawa et al. 2011).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: China


View distribution map in BerkeleyMapper.
Pachytriton moi is found in the Northeastern Guangxi Zhuang Autonomous region. This species has only been seen at Mt. Mao’er, Ziyuan County in Huaping Nature Reserve in Longsheng Gezu Autonomous County, and was collected at an elevation of 900 -1500 m from a montane stream (Nishikawa et al. 2011).

Life History, Abundance, Activity, and Special Behaviors
Pachytriton moi is probably nocturnal. The adult male individual was collected at ca. 2200 h in a montane stream, four to five meters from the riverbank. Juveniles were found under gravel in a stream head and swimming in small plunge pools near the stream both in the daytime and nighttime. Eggs and larvae have not been found, so its life history is poorly known. Breeding seems to start by late spring and possibly extends into early summer, as the individual had swollen testes in mid-March. Several Hygrobates mites were found around the hindlimbs and cloaca (Nishikawa et al. 2011).

Pachytriton species are known to be territorial in captivity and bite marks and scars were found on wild caught Pachytriton moi indicating the same may be true in this species. Territoriality may also explain why Pachytriton moi is able to live in sympatry with Pachytriton inexpectatus, as this is the only known instance of sympatry in Pachytriton species (Nishikawa et al. 2011).

Trends and Threats
Pachytriton moi is more rare than the sympatric species, Pachytriton inexpectatus and may be exploited by the pet trade (Nishikawa et al. 2011).

Relation to Humans
Pachytriton species are very popular in the pet trade but it is unclear if Pachytriton moi has been sold in the pet trade (Nishikawa et al. 2011).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Prolonged drought
Drainage of habitat
Intentional mortality (over-harvesting, pet trade or collecting)

The species authority is: Nishikawa, K., Jiang, J.P., Matsui, M. (2011) “Two new species of Pachytriton from Anhui and Guangki, China (Amphibia: Urodela: Salamandridae).” Current Herpetology 30:15-31.

It was differentiated from other species by a combination of morphological characteristics and phylogenetic analysis using mitochondrial cytochrome b gene. It was placed in the family Salamandridae, subfamily Pleurodelinae, and the genus Pachytriton. Pachytriton moi forms the third major distinct clade of Pachytriton; the other two clades consist of Clade I: P. granulosis, P. brevipes, P. feii, P. archospotus, and P. sp (an undescribed pet shop species) and Clade II: P. inexpectatus (Nishikawa et al. 2011).

The species epithet, moi is in honor of Mr. Yun-Ming Mo of the Guangxi Natural History Museum and who was instrumental in field surveys and faunal diversity (Nishikawa et al. 2011).

The genus, Pachytriton, is endemic to the People’s Republic of China (Nishikawa et al. 2011).

The species within the genus, Pachytriton, may have experienced several instances of introgression (Nishikawa et al. 2011).


Nishikawa, K., Jiang, J.P., Matsui, M. (2011). "Two new species of Pachytriton from Anhui and Guangki, China (Amphibia: Urodela: Salamandridae)." Current Herpetology, 30, 15-31. [link]

Originally submitted by: Brenda Yee (first posted 2015-05-19)
Edited by: Ann T. Chang (2015-05-19)

Species Account Citation: AmphibiaWeb 2015 Pachytriton moi: Mo's Stout Newt; Pachytriton de Mo <> University of California, Berkeley, CA, USA. Accessed Mar 1, 2024.

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Citation: AmphibiaWeb. 2024. <> University of California, Berkeley, CA, USA. Accessed 1 Mar 2024.

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