The South China giant salamander (''Andrias sligoi'') may be the largest species of

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...

and the largest

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

in the world. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to southern

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

, mainly in the

Pearl River The Pearl River, also known by its Chinese name Zhujiang or Zhu Jiang in Mandarin pinyin or Chu Kiang and formerly often known as the , is an extensive river system in southern China. The name "Pearl River" is also often used as a catch-a ...

basin south of the

Nanling Mountains The Nanling (), also known as the Wuling (), is a major mountain range in Southern China that separates the Pearl River Basin from the Yangtze Valley and serves as the dividing line between south and central subtropical zones. The main range ...

. It is extremely endangered and may no longer exist in the wild.

Discovery and description

It was described in 1924 (as ''Megalobatrachus sligoi'') by Edward George Boulenger from a captive specimen held in the

London Zoo London Zoo, also known as ZSL London Zoo or London Zoological Gardens is the world's oldest scientific zoo. It was opened in London on 27 April 1828, and was originally intended to be used as a collection for science, scientific study. In 1831 o ...

. This individual was originally held in the

Hong Kong Zoological and Botanical Gardens The Hong Kong Zoological and Botanical Gardens is one of the oldest zoo A zoo (short for zoological garden; also called an animal park or menagerie) is a facility in which animals are kept within enclosures for public exhibition and often b ...

and may have originated from

Guangxi Guangxi (; ; Chinese postal romanization, alternately romanized as Kwanghsi; ; za, Gvangjsih, italics=yes), officially the Guangxi Zhuang Autonomous Region (GZAR), is an Autonomous regions of China, autonomous region of the People's Republic ...

Guangdong Province Guangdong (, ), alternatively romanized as Canton or Kwangtung, is a coastal province in South China on the north shore of the South China Sea. The capital of the province is Guangzhou. With a population of 126.01 million (as of 2020) ...

, and was likely one of many giant salamanders captured from the mainland and placed in the Botanical Gardens' fountain, all of which had escaped. During a particularly violent storm in April 1920, a large drain pipe in the Gardens burst, carving a large depression into the land that the escaped salamander was washed into. It was captured and kept in a large circular basin, where it was fed daily with live

tadpoles A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found in ...

and occasionally

beef Beef is the culinary name for meat from cattle (''Bos taurus''). In prehistoric times, humankind hunted aurochs and later domesticated them. Since that time, numerous breeds of cattle have been bred specifically for the quality or quantity ...

. The captured salamander was later seen by George Ulick Browne, the then-

Marquess of Sligo Marquess of Sligo is a title in the Peerage of Ireland. It was created in 1800 for John Browne, 3rd Earl of Altamont. The Marquess holds the subsidiary titles of Baron Mount Eagle, of Westport in the County of Mayo (created 10 September 1760), ...

, as he was touring the area. Browne persuaded the then-governor of

Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...

Reginald Edward Stubbs Sir Reginald Edward Stubbs (; 13 October 1876 – 7 December 1947) was a British colonial governor, who was once the Governor of Hong Kong. He caused controversy while Governor of Ceylon over the Bracegirdle Incident. Early life and educati ...

, to present the salamander to the

Zoological Society of London The Zoological Society of London (ZSL) is a charity devoted to the worldwide conservation of animals and their habitats. It was founded in 1826. Since 1828, it has maintained the London Zoo, and since 1931 Whipsnade Park. History On 29 ...

. Upon receiving the individual, Boulenger found it to be physically distinct from "''Megalobatrachus maximus''" (the former species into which his father,

George Albert Boulenger George Albert Boulenger (19 October 1858 – 23 November 1937) was a Belgian-British zoologist who described and gave scientific names to over 2,000 new animal species, chiefly fish, reptiles, and amphibians. Boulenger was also an active botani ...

, lumped both the

Japanese giant salamander The Japanese giant salamander (''Andrias japonicus'') is a species of fully aquatic giant salamander endemic to Japan. With a length of up to ,Chinese giant salamander The Chinese giant salamander (''Andrias davidianus'') is one of the largest salamanders and one of the largest amphibians in the world.

Taxonomy

Despite Boulenger's classification, the species was later synonymized with the Chinese giant salamander (''A. davidianus''), and eventually forgotten. However, a study published in 2018 found that the Chinese giant salamander actually consisted of numerous

clades A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, t ...

restricted to different

river basins A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...

, with many of them being distinct enough to be considered separate species. One of these clades was the unnamed Clade D, sister to the unnamed Clade U1. A 2019 study of museum specimens found that the South Chinese population of ''A. davidianus'' was referable to Clade D, likely represented a distinct species, and was the subject of Boulenger's initial study, and thus supported the revival of ''A. sligoi'' as a distinct species.

Size

It is possible that ''A. sligoi'' may be the largest extant amphibian today, a superlative generally attributed to ''A. davidianus''. The largest known ''Andrias'' specimen was a individual captured near

Guiyang Guiyang (; ; Mandarin pronunciation: ), historically rendered as Kweiyang, is the capital of Guizhou province of the People's Republic of China. It is located in the center of the province, situated on the east of the Yunnan–Guizhou Plateau, ...

Guizhou Province Guizhou (; formerly Kweichow) is a landlocked province in the southwest region of the People's Republic of China. Its capital and largest city is Guiyang, in the center of the province. Guizhou borders the autonomous region of Guangxi to the ...

in the early 1920s. Although historical specimens collected near Guizhou do not have enough usable DNA to identify the species they belong to, more recent specimens collected from the region cluster with ''A. sligoi'', meaning that the largest collected individual may have been an ''A. sligoi'', rather than ''A. davidianus'' or a related species.

Threats and conservation

The South China giant salamander is highly endangered by

overharvesting Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term app ...

due to its status as a delicacy and use in

traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of action ...

, and it is unknown if any wild populations survive today. A large commercial trade in the species and its relatives was already established by the late 20th century, and very large-scale farms now exist for breeding giant salamanders for food and medicinal purposes. Several specimens collected in the 1990s originate from outside the native range of the species, and likely represent either translocated individuals that escaped the trade or individuals donated by or purchased from traders. Indiscriminate farming may also promote hybridization between different species, further contaminating each species'

gene pool The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species. Description A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can surv ...

. For this reason, it has been proposed that ''A. sligoi'' be classified as Critically Endangered on the IUCN Red List. Proposed conservation actions include creating a separate management plan for ''A. sligoi'', identifying and protecting sites that remnant wild populations may possibly occur at, identifying captive individuals and preventing hybridization or translocation, and creating a genetically pure

founder population In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, using ...

for the purpose of

captive breeding Captive breeding, also known as captive propagation, is the process of plants or animals in controlled environments, such as wildlife reserves, zoos, botanic gardens, and other conservation facilities. It is sometimes employed to help species that ...

and release.

References

{{Taxonbar, from=Q67817252 Cryptobranchidae Amphibians described in 1924 Amphibians of China Traditional Chinese medicine