Funding for this research was provided by:
Guangdong Key Laboratory of Animal Conservation and Resource Utilization (GIABR-KF201702)
National Key Research and Development Project (2016YFC201200)
Received: 2 February 2018
Accepted: 8 May 2018
First Online: 23 May 2018
Compliance with ethical standards
: The authors declare that they have no competing interests.