Phylogeographic patterns and conservation implications of the endangered Chinese giant salamander.

Zhi‐Qiang Liang,Jiang Xie,Wei‐Tao Chen,Deng‐Qiang Wang,Ping He,Yuan‐An Wu,Shu‐Huan Zhang,Juha Merilä,Qi‐Wei Wei,Chuan‐Wu Li,Shun‐Ping He,Chong‐Rui Wang

doi:10.1002/ece3.5014

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.

Highlights

The Chinese giant salamander (Andrias davidianus) (Figure 1) is the largest extant amphibian species in the world, and it is entirely aquatic and endemic to the montane areas of central and southern China at approximately 23.5–35°N and 100–120°E (Fu, 1993)
We characterized phylogeographic pattern and differentiation of A. davidianus on the basis of mitochondrial DNA and nuclear DNA utilizing a large number of wild‐caught animals sampled from area covering most of its native distribution range
This study investigates the phylogeographic patterns of A. davidi‐ anus populations and presents some conservation implications for this endangered species based on a wide geographic sampling and using multiple markers

Summary

| INTRODUCTION

The Chinese giant salamander (Andrias davidianus) (Figure 1) is the largest extant amphibian species in the world, and it is entirely aquatic and endemic to the montane areas of central and southern China at approximately 23.5–35°N and 100–120°E (Fu, 1993). In addition to the complex drainage systems (e.g., the Yangtze River, Yellow River, Pearl River, and several coastal rivers; Figure 2b), these regions raise high species diversity for Amphibians (Zhang, 1999). These regions represent an ideal system for investigating that how these environment factors drive the genetic diversity and diversification in amphibians. We characterized phylogeographic pattern and differentiation of A. davidianus on the basis of mitochondrial DNA (mtDNA) and nuclear DNA (nuDNA) utilizing a large number of wild‐caught animals sampled from area covering most of its native distribution range (http://maps.iucnredlist.org). The main aims were (a) to assess how many distinct genetic clades the A. davidianus consist of in the natural species ranges and where they occur, (b) to explore what factors have shaped the patterns of genetic variability and differentiation in A. davidianus, and (c) to offer recommendations for A. davidianus conservation

| METHODS AND MATERIALS

| DISCUSSION

Findings

CONFLICT OF INTEREST