AmphibiaChina 中国两栖类.

Conservation Status (definitions)

IUCN Red List Status Account CITES No CITES Listing National Status None Regional Status None

Description

DESCRIPTION:

Tylototriton tongziensis is a newt found in the Guizhou Province of China and described from four males, two females, and two larva. Its snout-vent length ranges from 61.1 - 65.9 mm in males and 66.7 - 69.2 mm in females, and its total length ranges 120.5 - 135.1 mm in males and 123.5 - 127.6 mm in females. The head is a little longer than wide. It has a nearly square snout and a head that is slightly concave at the top. The snout is truncated and extends past the lower lip in the dorsal view. The nostrils are near the snout. Its eyes protrude dorsolaterally, and its inter-orbital space is larger than its inter-nasal space. The eyes are anterior to the joint of jaw articulation. It does not have a labial fold. It has a flat oral fissure with fine teeth on the edge of its jaw, and long, upside-down-V-shaped vomerine teeth. Its tongue is oval and free at the lateral edges but nearly fixed at the bottom. Its moderate bony dorsolateral ridges are prominent and begin above the snout, extending to the anterior edge of the parotoids, where they thickly scroll toward the midline. It has enlarged parotoids that extend backwards and a distinct, thin mid-dorsal ridge on its head. It also has a thick gular fold on its round neck. It has a stout body with no small glands protruding from its lateral side, slightly rough skin displaying mild segmentation, and indistinct rib nodules. Its skin is rough and covered in small tubercles, but the ventral side of its limbs and the ventral edge of its tail are smooth. The labial margin and the distal limbs are also smooth. The ventral tubercles are dense and distinct, whereas, on the lateral dorsum, they form lines from the base of the tail to the shoulder without separation between them. It has slender limbs and lacks webbing between the digits. Its fingers extend past its snout when the forelimb is adpressed towards its head, and when the limbs are adpressed towards each other along its body the digits overlap. The relative finger lengths are III > II > IV > I and the relative toe lengths are III > IV > II > I > V. The area around the long, narrow cloaca is somewhat bulbous. Its tail is shorter than the snout-vent length, thin, laterally compressed, and the tip is acuminated (Li et al. 2022).

DIAGNOSIS:

Tylototriton tongziensis is most closely related to T. dabienicus, but can be distinguished because T. dabienicus has a longer total length in females (134.9 - 155.5 mm) (Chen et al. 2010). Further, T. dabienicus’ forelimbs only reach the anterior corners of its eyes when adpressed along its head, and the digits do not touch when the limbs are adpressed along its body towards each other (Li et al. 2022). Tylototriton tongziensis and T. anhuiensis differ because when T. anhuiensis’ forelimbs are adpressed along its body, they meet but do not overlap (Qian et al. 2017). Tylototriton tongziensis females are shorter in total length than T. broadoridgus females (138.9 - 162.5 mm) (Li et al. 2022) and T. broadoridgus does not have a gular fold, nor do its digits touch or overlap when its limbs are adpressed towards each other. Both T. maolanensis males and females have a longer total length, and have separated, distinct warts on their body sides. Female T. tongziensis have a shorter snout-vent lengths than female T. daloushanensis (70.5 - 100.3 mm), and T. daloushanensis’ fingertips reach between the eyes and nostrils when adpressed along its sides. Tylototriton tongziensis has a gular fold and T. wenxianensis does not. Lastly, both T. liuyangensis and T. lizhengchangi have longer total lengths in females (138.6 - 154.2 mm and 150.0 - 156.5 mm, respectively).

COLORATION:

In life, T. tongziensis is black or brown with orange on the distal and ventral surfaces of its digits, on the ventral edge of its tail, and on the peripheral area of its cloaca. The orange of the ventral edge of the tail and the peripheral area of its cloaca are connected. In preservative, the orange fades to a cream color, and the rest of the coloration remains the same (Li et al. 2022).

VARIATION:

Distribution and Habitat

Country distribution from AmphibiaWeb's database: China

View distribution map in BerkeleyMapper.

As of 2022, T. tongziensis has only been found in the Huanglian Nature Reserve in Tongzi County, Guizhou Province, China at an elevation of about 1530 m above sea level. They are found in a mountain stream in the midst of an evergreen broadleaf forest (Li et al. 2022).

Life History, Abundance, Activity, and Special Behaviors
Both adults and larvae can be found at the bottom of clear ponds with muddy bottoms in the Huanglian Nature Reserve during the months of May through August. These ponds are relatively shallow and small, reaching depths of about 20 cm, and dimensions of about 2 by 3 m (Li et al. 2022).

Larva
Two fully grown larvae were collected with total lengths of 36.9 and 41. 3 mm and snout-vent lengths of 20.6 and 21.4 mm. The larvae have slender bodies that are laterally compressed. Its head is longer than it is wide, with large eyes and three pairs of external gills. The skin is smooth. Its costal grooves are indistinct. The tail is laterally compressed with the tall dorsal fin beginning just posterior to the head. The short, thick ventral tail fin starts at the cloaca and runs the entire length of the tail (Li et al. 2022).

In life, the larval body is black-brown - becoming darker towards the tail. The digits are transparent, and the black tail has small yellow spots (Li et al. 2022).

Trends and Threats
As of 2022, the ponds in the Huanglian Nature Reserve, where the species is found, are the only locality from which this species is known. Because the Reserve habitats are under threat from the developing tourism industry nearby, and the population surveyed was small, the recommended IUCN threat status is “Critically Endangered” (Li et al. 2022).

Possible reasons for amphibian decline

General habitat alteration and loss
Urbanization

Comments

PHYLOGENETIC RELATIONSHIPS:

Bayesian and Maximum Likelihood analyses of 16S and ND2 mtDNA and two nuclear genes (NCX1 and BDNF) found that T. tongziensis is sister to T. dabienicus. Together they form a clade that is sister to T. anhuiensis. The next most closely related species is T. broadoridgus, then T. maolanensis. The clade formed by all the aforementioned species is sister to the clade formed by T. daloushanensis and T. wenxianensis with a clade formed by T. liuyangensis and T. lizhengchangi following (Wang et al. 2018, Li et al. 2022).

ETYMOLOGY:

The species epithet, “tongziensis,” was derived from the locale in which it was first found, Tongzi County, Guizhou Province, China (Li et al. 2022).

References

Chen, X., Wang, X. Tao, J. (2010). A new subspecies of genus Tylototriton from China (Caudata, Salamandridae). Acta Zootaxonomica Sinica/Dong wu fen lei xue bao Beijing, 35, 666–670.

Li, S.-Z., J. Liu, S. Shi, G. Wei, Wang, B. (2022). Description of a new species of the newt genus Tylototriton sensu lato (Amphibia: Urodela: Salamandridae) from southwestern China. Zootaxa, 5128, 248–268. [link]

Qian L, Sun X, Li J, Guo W, Pan T, Kang X, Wang H, Jiang J, Wu J, Zhang B. (2017). A new species of the genus Tylototriton (Amphibia: Urodela: Salamandridae) from the Southern Dabie Mountains in Anhui Province. Asian Herpetological Research, 8, 151–164. [link]

Wang B., Nishikawa K., Matsui M., Nguyen T.Q., Xie F., Li C., Khatiwada J.R., Zhang B., Gong D., Mo Y., Wei G., Chen X., Shen Y., Yang D., Xiong R., Jiang J. (2018). Phylogenetic surveys on the newt genus Tylototriton sensu lato (Salamandridae, Caudata) reveal cryptic diversity and novel diversification promoted by historical climatic shifts. Peer J, 6e, 4384. [link]

Species Account Citation: AmphibiaWeb 2023 Tylototriton tongziensis: English: Tongzi Knobby Newt; Chinese: Tong Zi You Yuan. <https://amphibiaweb.org/species/9537> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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