AmphibiaChina 中国两栖类.

Description

DESCRIPTION:

Cynops glaucus is a small statured salamander with an oval-shaped head and a rounded, blunt snout. The total length, from snout to tail, of males ranges from 65.17 mm to 74.50 mm and averages 69.28 mm. The total length of females ranges from 83.40 mm to 95.93 mm and averages at 89.67 mm. The snout-vent length of males range from 34.01 mm to 39.41 mm and females from 42.59 mm to 48.84 mm. The nostrils are minute, but visible and are located on the tip of its snout. Its eyes are also small and do not extend past the sides of its head. A slight ridge extends from the back of each eye along the head. Most of the body is covered with fine granulated skin. Individuals have four fingers on each hand and five toes on each foot, all slender and lacking webbing. Their relative digit lengths are 1 < 4 < 2 < 3 for the fingers and 1 < 5 < 2 < 4 < 3 for the toes (Yuan et al. 2013).

DIAGNOSIS:

Cynops glaucus is mainly differentiated from other Cynops species by its coloration. The blue-gray mottling on its dorsum is unique among Cynops species. The pattern of orange spots and dark patches on the underside of the chin, vent, and limbs can also be diagnostic (Yuan et al. 2013). Cynops fundingensis, a species found in a similar region as C. glaucus, has a pronounced vertebral ridge instead of the subtle one found on C. glaucus (Wu et al. 2010). Cynops eniscauda, Cynops orientalis, Cynops orphicus and Cynops pyrrhogaster have a more conspicuous vertebral ridge than C. glaucus. Cynops orientalis is also distinguishable by its smooth skin. Cynops chenggongensis and C. cyanurus both have an orange spot posterior to their eyes, which C. glaucus lacks (Yuan et al. 2013).

COLORATION:

In life, irregular blue-gray mottling can be seen on the brown dorsum of C. glaucus from snout to tail and along all four limbs. Extremely bright ventral coloration is exhibited through orange blotching and striping. There are two bright orange, continuous, medial ventral stripes, one on the tail and one between the vent and the forelimbs. In preserved specimens, the blue-gray mottling is still observable, but the dorsal coloration darkens to a brownish black. Additionally, the blotching and striping on the underside changes from orange to off-white (Yuan et al. 2013).

VARIATION:

Males are smaller in size compared to females and their tails are shorter and wider. Ventral coloration and patterning can vary among individuals. While most specimens display bright orange blotching, orangish red and yellow has been observed on occasion. The number and shape of orange ventral blotches can differ depending on the specimen (Yuan et al. 2013).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: China

View distribution map in BerkeleyMapper.

The first specimens of C. glaucus were found in Southeast China in Wuhua County, Guangdong, China. Some were found on Mt. Lianhua at elevations varying from 698 - 900 m. This species of newt lives in marshy, wetland areas near forests. These areas are tropical and subtropical. The wetlands can vary from natural freshwater marshes, to irrigated lands, to places with frequent, shallow puddles. The pools of water are found among shrubs and grasses, and often contain decomposing vegetation (Yuan et al. 2013).

Life History, Abundance, Activity, and Special Behaviors
This species is rare (IUCN 2019). Based on similar species and the habitat where the type specimens of C. glaucus were found, this species is most likely semi-aquatic. It associates with stillwater areas, like ponds and puddles (Yuan et al. 2013).

This species does display aposematic coloration, but it is unknown whether or not the coloration is a true signal of toxicity or a case of Batesian mimicry. Several other species in the genus Cynops, such as C. pyrrhogaster and C. eniscauda are quite toxic, secreting tetrodotoxin from glands in their skin when threatened. Given the shared evolutionary history of the members of the genus Cynops, it seems likely that C. glaucus is toxic as well (Hanifin 2010).

Trends and Threats
Habitat loss is not a problem for C. glaucus near Mt. Lianhua. The forest in the area is subject to strict governmental protections and thus habitat is intact. One of the reasons the researchers were unable to find other locations where C. glaucus occurs was the extremely dense forest. However, habitat loss or change would probably have a significant effect on C. glaucus populations due to their affinity for shallow, still puddles with shrub cover (Yuan et al. 2013).

In 2016 - 2017 researchers testing salamander skin samples for chytrid fungus, Batrachochytrium salamandrivorans sampled 29 C. glaucus individuals from two locations. None of the individuals tested positive for the fungus suggesting it has not yet spread to their population (Yuan et al. 2018). Since the range extent and population numbers of C. glaucus is still somewhat unknown it is hard to predict how big of an effect chytrid fungus could have on the population (Yuan et al. 2013).

Relation to Humans
Other species of Cynops salamander species are harvested for the pet trade, but it is unclear if C. glaucus is as well. One heavily traded Cynops species, C. orientalis, is also found in southeast China suggesting that collection occurs within the range of C. glaucus. Since many of the Cynops species look somewhat similar, it seems likely that C. glaucus could be collected and traded without detection as a different species. However, there is no concrete evidence for traded C. glaucus specimens at this time (Yuan et al. 2018).

Comments

PHYLOGENETIC RELATIONSHIPS:

Maximum Parsimony, Maximum Likelihood, and Bayesian Inference analyses of ND2 and COI suggests that all newts in the Cynops genus that are found in China share a single common ancestor. However, the sister species to C. glaucus group remains unclear as it forms a polytomy with C. cyanurus and a clade composed of C. fudingensis, C. orientalis and C. orphicus. Two Japanese species, C. ensicauda and C. pyrrhogaster are sister to the species from China (Yuan et al. 2013).

ETYMOLOGY:

The genus, ‘Cynops’, means ‘marine animal’ referring to their association with water, albeit freshwater (World of Dictionary - World of Dictionary. “Cynops.” https://worldofdictionary.com/dict/latin-english/meaning/cynops. Accessed 25 Feb. 2022.).

The species epithet, ‘glaucus’, is Latin for ‘of a light-bluish gray color,’ referring to the bluish-grey dorsal coloration of this species (Yuan et al. 2013, Merriam-Webster Dictionary).

References

Hanifin, C. T. (2010). “The chemical and evolutionary ecology of tetrodotoxin (TTX) toxicity in terrestrial vertebrates.” Marine Drugs, 8(3), 577-593. [link]

IUCN SSC Amphibian Specialist Group. 2020. "Cynops glaucus." The IUCN Red List of Threatened Species 2020: e.T78516909A122172237. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T78516909A122172237.en. Accessed 25 Feb. 2022. https://www.iucnredlist.org/species/78516909/122172237.

Merriam-Webster Dictionary. “Glaucous.” Merriam-Webster, https://www.merriam-webster.com/dictionary/glaucous. Accessed 25 Feb. 2022.

Wu, Y., Wang, Y., Jiang, K. and Hanken, J. (2010). ''A new newt of the genus Cynops (Caudata: Salamandridae) from Fujian Province, southeastern China.'' Zootaxa, 2346, 42-52.

Yuan, Y. et al. (2018) “Widespread occurrence of an emerging fungal pathogen in heavily traded Chinese urodelan species.” Conservation Letters 11(4): e12436. [link]

Yuan, Y., Jiang, K., Ding, L, Zhang, L., Che, J. (2013). “A new newt of the genus Cynops (Caudata: Salamandridae) from Guangdong, China.” Asian Herpetological Research 4(2): 116–123 [link]

Species Account Citation: AmphibiaWeb 2022 Cynops glaucus: Bluish Grey Newt; Huilan Rongyuan (Chinese name) <https://amphibiaweb.org/species/8068> University of California, Berkeley, CA, USA. Accessed Nov 24, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Nov 2024.

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