Phylogeographic patterns and conservation implications of the endangered Chinese giant salamander

Abstract

Understanding genetic diversity patterns of endangered species is an important premise for biodiversity conservation. The critically endangered salamander Andrias davidianus , endemic to central and southern mainland in China, has suffered from sharp range and population size declines over the past three decades. However, the levels and patterns of genetic diversity of A. davidianus populations in wild remain poorly understood. Herein, we explore the levels and phylogeographic patterns of genetic diversity of wild‐caught A. davidianus using larvae and adult collection with the aid of sequence variation in (a) the mitochondrial DNA (mtDNA) fragments ( n = 320 individuals; 33 localities), (b) 19 whole mtDNA genomes, and (c) nuclear recombinase activating gene 2 ( RAG2 ; n = 88 individuals; 19 localities). Phylogenetic analyses based on mtDNA datasets uncovered seven divergent mitochondrial clades (A–G), which likely originated in association with the uplifting of mountains during the Late Miocene, specific habitat requirements, barriers including mountains and drainages and lower dispersal ability. The distributions of clades were geographic partitioned and confined in neighboring regions. Furthermore, we discovered some mountains, rivers, and provinces harbored more than one clades. RAG2 analyses revealed no obvious geographic patterns among the five alleles detected. Our study depicts a relatively intact distribution map of A. davidianus clades in natural species range and provides important knowledge that can be used to improve monitoring programs and develop a conservation strategy for this critically endangered organism.

Future climate change will severely reduce habitat suitability of the Critically Endangered Chinese giant salamander

“…A further caveat in model interpretation could be clade‐specific variability and phenotypic plasticity. Yan et al () and Liang et al () uncovered seven divergent mitochondrial clades in A. davidianus . Besides, Riddell, Odom, Damm, and Sears () revealed that plasticity may contribute in buffering salamander species from climate change.…”

“…While the effects of climate change are largely studied in surface habitats, the impacts on subterranean habitats are still poorly explored (Mammola, Cardoso, et al, ; Mammola, Piano, et al, ). Andrias davidianus primarily exploits habitats at the surface/subterranean interface for breeding (Liang et al, ; Luo et al, ). The temperature increment in these transitional subterranean habitats is expected to parallel the external one almost synchronically (Mammola, Piano, et al, ).…”

“…Our study area is located in central and southern China, ranging from 100 to 124°E and 23.5 to 36°N (Figure ). We determined the extent of the accessible area by considering the known geographical distribution of A. davidianus (Fu, ; Liang et al, ), and the distribution predicted by a previous SDM study focusing on this species (Chen et al, ).…”

“…With the aid of local management agencies of A. davidianus , we recorded the presence of the species in both rivers and from natural populations breeding in caves. In fact, while this is mostly a surface‐dwelling species, 11 natural breeding caves of A. davidianus have been reported in five provinces in China over the past 15 years (Liang et al, ; Liang, Zhang, Wang, Wei, & Wu, ; Luo et al, ). As a result of the sampling activities, we assembled a dataset of 50 spatially unique occurrence records, scattered through 15 provinces in China (Table S1).…”

“…During the reproductive season, females lay eggs in their dens, and males guard eggs until they are hatched (Luo, Tong, et al, ). Given that this species generally breeds in caves and other underground voids, A. davidianus is regarded as a facultative subterranean species (Liang et al, ; Luo, Zhang, Liu, Chen, & Gan, ). Andrias davidianus is a Critically Endangered species (IUCN, ; Turvey et al, ) and is listed in the Appendix I of Convention on International Trade in Endangered Species of Wild Fauna and Florax.…”