Andrias jiangxiensis Lu, Wang, Chai, Yi, Peng, Murphy, Zhang & Che, 2022
English: Jiangxi Giant Salamander; Chinese: 江西大鲵
|Species Description: Chai J, Lu C-Q, Yi M-R, Dai N-H, Weng X-D, Di M-X, Peng Y, Tang Y, Shan Q-H, Wang K, Liu H-Z, Zhao H-P, Jin J-Q, Cao R-J, Lu P, Luo L-C, Murphy RW, Zhang Y-P, and Che J. 2022. Discovery of a wild, genetically pure Chinese giant salamander creates new conservation opportunities. Zoological Research 43: 469–480.|
The skin of the head and the lower jaw are smooth except for the irregularly scattered, small tubercles positioned to the side of the temples and neck, which increase in number, posteriorly. This skin description can be similarly applied to the rest of the body. The skin of the body is mostly smooth except for large tubercles that run dorsolaterally above the lateral fold on either side of the vertebrae, and run from the neck to the base of the tail. In preservation, the tubercles along the body become indistinct (Chai et al. 2022).
The body of the Jiangxi Chinese giant salamander is robust, elongated, and less dorsally compressed than the head. Costal grooves run along the body, with the vertebral groove visible on ¾ of the back of the body, and in preservation, the grooves become less distinct. In terms of folds, the neck fold is developed prominently from the corner of the mouth to the posterosuperior axillary. Furthermore, a transverse gular fold across the neck is visible and without clear glands. The lateral body folds are well-developed and extend to the base of the tail; they are weak in the anterior region and do not connect with the neck fold and extend to the base of the tail (Chai et al. 2022).
In terms of limbs, A. jiangxiensis have dorsoventrally compressed, short, and robust limbs with visible lateral skin folds, especially near the hips. The hind limbs are longer and stronger than the forelimbs. Like the rest of the body, the hands and feet of A. jiangxiensis are dorsally compressed. The tips of the fingers and toes are enlarged and rounded, with these tips, and the palms, being covered with a dark carotin layer. The hands have four fingers with no webbing, with the fourth finger having a lateral skin fringe extending from the limb’s lateral fold. The finger length formula is II > III > I > IV. The feet have five toes, with basal webbing, prominent lateral fringes on the last three toes, and a toe length formula of III > IV > II > V > I (Chai et al. 2022).
Lastly, the tail of the A. jiangxiensis is short, muscular, and thick at the base, but it gradually flattens out towards the back. Its dorsal fin is developed well, while the ventral fin is more reduced in size. The tail length ranges from 191 - 208 mm, which is smaller than the snout-vent length and total length. Meanwhile, the tail height ranges from 60.7 - 76.2 mm (Chai et al. 2022).
Morphological comparisons of the holotypes of all the known Chinese Andrias species, used to avoid confusion due to the hybrids or translocated animals, confirm that Jiangxi Chinese giant salamanders are distinguishable from all Andrias species. In comparison to A. japonicus, the Japanese giant salamander that has dense, visible tubercles, A. jiangxiensis has a smoother head and indistinct tubercles. This smooth head and indistinct, irregular tubercles on the lower jaw also separate A. jiangxiensis from A. davidianus (which has a rough lower jaw with distinct, regularly arranged tubercles). Lastly, having smooth skin on the snout and around the eye and a distinct finger length formula distinguish A. jiangxiensis from A. sligoi, as A. sligoi has distinct tubercles on its snout and around the eyes and roughly equal finger lengths (Chai et al. 2022).
In life, A. jiangxiensis has a red-brown dorsum with either large continuous or large discontinuous black patches with black spots dispersed between the patches. These patches decrease and break apart from the mid-body to head and from mid-body to tail. In addition, there are small white spots with a tan outer edge throughout the body. While viewed ventrally, the surface is a grayish brown and black spots can be seen within the jaw region. A grayish white color can be found around the eyes, which have gold irises and black markings.
In preservation, the bright tints of the body are faded, in addition to the dorsum fading to a grayish brown and the abdomen to a gray shade. The tips of the fingers and toes, with a horny epidermis, and the palms of the hands, are also a brown color. The white spots with tan edges, the large black patches, and the black spots, however, are still visible (Chai et al. 2022).
There is no significant variation in morphology and coloration between adult A. jiangxiensis. However there is variation in coloration between life stages. Juveniles less than 30 cm long are mostly spotted, but after growing past 40 cm, larger patches develop, thus resembling adult A. jiangxiensis (Chai et al. 2022).
Distribution and Habitat
Andrias jiangxiensis is endemic to the Jiulingshan National Nature Reserve, located in the Daqi Mountain of Jiangxi, China. The reserve is a protected riverine habitat, containing many forested mountains and streams, mostly untouched by human activities. The streams themselves are medium-sized, with an 8 - 10 m width and 0.1 - 1.5 m depth. Rocky substrates can be found at the bottom of the streams, which also have inconsistent water flow due to flash floods in the summer and droughts in the winter. Natural caves, developed by fallen wood, cracks among wood, or tree roots can also be found nearby the streams (Chai et al. 2022).
Some individuals in the species exist as breeding stock in local farms and have been translocated to other sites (Chai et al. 2022).
Life History, Abundance, Activity, and Special Behaviors
Nocturnal in nature, A. jiangxiensis hunts at night for fish, aquatic insects, frogs, and crustaceans within the freshwater ecosystem they inhabit (Chai et al. 2022). Such behavior is similar to other Andrias clades, who are regarded as top predators in their freshwater environments (Turvey et al. 2019).
The coloration on the Jiangxi Chinese giant salamander allows them to blend into the rocks at the bottom of the stream to aid in hunting (Chai et al. 2022).
Andrias jiangxiensis are observed to breed from within caves in mid-September. The larvae have initial feeding periods from December to February, and feeding peaks in late January. Larvae usually emerge from the caves 2 months after hatching and start scattering into the stream after (Chai et al. 2022).
Larvae initially feed from December to February and peak in late January (Chai et al. 2022).
Observations of larvae show they usually leave the breeding caves two months after hatching and disperse into the outside stream. A peak of over 100 larvae leaving the caves per day can be seen in February (Chai et al. 2022).
Trends and Threats
Andrias jiangxiensis is extremely endangered due to continual exploitation of the species by humans for consumption or medicine. Especially during China’s transition to a capitalist economy after the 1950s, A. jiangxiensis and other Andrias clades endangerment heightened. From the 1960s - 1970s, the traditionally consumed salamanders were allowed to be translocated by the Chinese people to supply the luxury market (Turvey et al. 2018). In the early 2000s, commercial farms for the salamanders started developing. These farms utilized ex situ propagation to breed the salamanders, which resulted in artificial hybridization. Some of the salamanders in farms (both pure and hybrids) were translocated resulting in genetic admixture in the wild. Hybrids are observed to have severe reductions in fitness, likely due to their potential genetic incompatibilities (Chai et al. 2022). The “salamander rush” from the potential profit in farming Chinese giant salamanders only enabled the genetic mixing of the salamanders, in addition to poaching and spread of disease from farmed or translocated salamanders (Turvey et al. 2018).
At the time of the species description, A. jiangxiensis, located in Jiulingshan National Nature Reserve, was the only indigenous purebred population. This population itself is isolated, small, and fragmented. The species is used as breeding stock in small local farms, thus resulting in hybrids with A. jiangxiensis genetic signatures. These hybrids have not been released back into the native wild population (Chai et al. 2022).
Further threats to the Jiangxi Chinese giant salamander result from habitat destruction in combination with their small, isolated populations. Ranging from farm chemical runoff, climate change, or the noticeable building of a dam in the downstream habitat outside the natural reserve. The A. jiangxiensis population is incredibly vulnerable to these changes (Chai et al. 2022; Turvey et al. 2018).
In response to the endangerment of the Chinese giant salamanders, China created 47 closed national natural reserves for the in situ protection of the salamanders. One of these reserves can be assumed to be the Jiulingshan National Nature Reserve. Propositions for large-scale genetic assessments to PIT tag purebred Chinese giant salamanders are also in proposal by scientists to preserve the wild, indigenous genetic integrities of the salamanders (Chai et al. 2022).
Relation to Humans
Andrias jiangxiensis, like other Chinese giant salamanders, have been consumed for food and utilized in medicine by humans for centuries, and they were prominently seen as a luxury good in the 1970s. The “salamander rush” in the early 2000s enabled a commercial farming business for Chinese giant salamanders, whose ex situ propagation resulted in interspecies hybridization (Chai et al. 2022; Turvey et al. 2018). However, the price of Chinese giant salamanders, now considered legal for consumption if farm-bred, has resulted in the Chinese giant salamander no longer being seen as a luxury good. 50 interviews within 1 km of the Jing’an County display such a shift, as only nine interviewers admitted to eating the salamanders out of curiosity and not as a dietary staple. Six interviewers could also distinguish between the morphologies of indigenous and introduced Chinese giant salamanders in the Jing’an County. These individuals found the A. jiangxiensis to be the “more beautiful” salamander. Thereby, the Jing’an County noticeably holds a local cultural pride to the A. jiangxiensis (Chai et al. 2022).
Possible reasons for amphibian decline
General habitat alteration and loss
China’s A. davidianus and Japan’s A. japonicus were believed to be the only Andrias clades until 2018 (Turvey et al. 2019). Through the use of Bayesian Inference of COI, D-loop mtDNA, and partial cytb, in addition to nuclear single nucleotide polymorphisms (SNPs) of modern, wild-caught samples, at least five cryptic species of Chinese giant salamanders were identified by Yan et al. (2018). One of these cryptic species was described as A. jiangxiensis in 2022. Chai et al. (2022) confirmed the species by utilizing principle components analysis, genetic clustering, and a maximum likelihood network of genomic SNPs.
The epithet “ jiangxiensis” refers to the endemicity of the new species to Jiangxi, China (Chai et al. 2022).
OTHER INTERESTING INFORMATION:
Andrias jiangxiensis is the only known Chinese giant salamander species that currently has a genetically pure population reproducing in the wild. There is very little data on the Chinese giant salamander in the wild because of inadequate investigations, absences of the salamanders in surveyed areas, and unstable wild populations. Andrias jiangxiensis provides a crucial chance for documenting the natural history of their larvae, juveniles, and adults to learn about their habitat ecology and life history. Therefore, data collected on A. jiangxiensis demonstrates the importance of undisturbed habitats in relation to their reproductive and feeding behavior, which can be used to manage conservation efforts for Chinese giant salamanders (Chai et al. 2022).
Chai, J., Lu, C., Yi, M., Dai, N., Weng, X., Di, M., Peng, Y., Tang, Y., Shan, Q., Wang, K., Liu, H., Zhao, H., Jin, J., Cao, R., Lu, P., Luo, L., Murphy, R., Zhang, Y., Che, J. (2022). "Discovery of a wild, genetically pure Chinese giant salamander creates new conservation opportunities." Zoological Research, 43(3), 469-480. [link]
Turvey, S.T., Chen, S., Tapley, B., Wei, G., Xie, F., Yan, F., Yang, J., Liang, Z., Tian, H., Wu, M., Okada, S., Wang, J., Lü, J., Zhou, F., Papworth, S.K., Redbond, J., Brown, T., Che, J., Cunningham, A.A. (2018). “Imminent extinction in the wild of the world’s largest amphibian.” Current Biology, 28(10), R581–R598. [link]
Yan, F., Lü, J., Zhang, B., Yuan, Z., Zhao, H., Huang, S., Wei, G., Mi, X., Zou, D. Xu, W., Chen, S., Wang, J., Xie, F., Wu, M., Xiao, H., Liang, Z., Jin, J., Wu., S., Xu, C., Tapley, B., Turvey, S., Papenfuss, T.J., Cunningham, A.A., Murphy, R.W., Zhang, Y., Che, J. (2018). "The Chinese giant salamander exemplifies the hidden extinction of cryptic species." Current Biology, 28(10), R590–R592. [link]
Originally submitted by: Hong Nguyen (2022-10-10)
Description by: Hong Nguyen (updated 2022-10-10)
Distribution by: Hong Nguyen (updated 2022-10-10)
Life history by: Hong Nguyen (updated 2022-10-10)
Larva by: Hong Nguyen (updated 2022-10-10)
Trends and threats by: Hong Nguyen (updated 2022-10-10)
Relation to humans by: Hong Nguyen (updated 2022-10-10)
Comments by: Hong Nguyen (updated 2022-10-10)
Edited by: Ann T. Chang (2022-10-10)
Species Account Citation: AmphibiaWeb 2022 Andrias jiangxiensis: English: Jiangxi Giant Salamander; Chinese: 江西大鲵 <https://amphibiaweb.org/species/9542> University of California, Berkeley, CA, USA. Accessed Sep 22, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Sep 2023.
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