Abstract
Inaccurate taxonomic assessment of threatened populations can hinder conservation prioritization and management, with human‐mediated population movements obscuring biogeographic patterns and confounding reconstructions of evolutionary history. Giant salamanders were formerly distributed widely across China, and are interpreted as a single species, Andrias davidianus. Previous phylogenetic studies have identified distinct Chinese giant salamander lineages but were unable to associate these consistently with different landscapes, probably because population structure has been modified by human‐mediated translocations for recent commercial farming. We investigated the evolutionary history and relationships of allopatric Chinese giant salamander populations with Next‐Generation Sequencing methods, using historical museum specimens and late 20th‐century samples, and retrieved partial or near‐complete mitogenomes for 17 individuals. Samples from populations unlikely to have been affected by translocations form three clades from separate regions of China, spatially congruent with isolation by either major river drainages or mountain ranges. Pliocene–Pleistocene divergences for these clades are consistent with topographic modification of southern China associated with uplift of the Qinghai‐Tibet Plateau. General Mixed Yule Coalescent model analysis indicates that these clades represent separate species: Andrias davidianus (Blanchard, 1871) (northern Yangtze/Sichuan), Andrias sligoi (Boulenger, 1924) (Pearl/Nanling), and an undescribed species (Huangshan). Andrias sligoi is possibly the world's largest amphibian. Inclusion of additional reportedly wild samples from areas of known giant salamander exploitation and movement leads to increasing loss of biogeographic signal. Wild Chinese giant salamander populations are now critically depleted or extirpated, and conservation actions should be updated to recognize the existence of multiple species.
Highlights
The conservation of highly threatened taxa is dependent upon the availability of robust baseline information on key population pa‐ rameters (Segan, Bottrill, Baxter, & Possingham, 2011; Sutherland, Pullin, Dolman, & Knight, 2004)
We only included sequence data for (a) the five pre‐1922 museum samples which were collected before large‐scale transloca‐ tions of giant salamanders took place across China; and (b) four 1992 samples from Huangshan, which have previously been identified as a distinct clade, and are from a geographic region not represented by older museum collections and which was economically undeveloped and considered unlikely to have been affected by translocations in the 1990s before development of large‐scale salamander farming (Murphy et al, 2000)
Given the limited number of sampling localities associated with historical samples that yielded DNA, and the lack of precise local‐ ity data to identify the river system from which the Guangdong/ Guangxi and Huangshan specimens originate, it is difficult to test between these two competing biogeographic hypotheses
Summary
The conservation of highly threatened taxa is dependent upon the availability of robust baseline information on key population pa‐ rameters (Segan, Bottrill, Baxter, & Possingham, 2011; Sutherland, Pullin, Dolman, & Knight, 2004). The most recent genetic study of wild‐caught and farmed Chinese giant salamander samples identified seven distinct lin‐ eages using mitochondrial genes (partial cytochrome b [cytb], COI, D‐loop) and nuclear SNPs (Yan, Lü, et al, 2018); some or all of these lineages were considered likely to represent cryptic species, revealing previously unsuspected levels of diversity within Chinese cryptobranchids These studies did not detail their findings against regional biogeographic patterns shown by other Chinese taxa and were unable to consistently associate distinct clades with different landscapes, which they attributed to recent human movement of giant salamanders around China mod‐ ifying local population structure and obscuring historical patterns of regional biogeographic differentiation (Murphy et al, 2000; Yan, Lü, et al, 2018). Our findings establish a new mitogenomic framework for understand‐ ing cryptobranchid diversity and diversification in the context of China's geological history and provide a new taxonomic assessment of Chinese giant salamanders to inform conservation management of the world's largest amphibians
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
