Biodiv Sci ›› 2020, Vol. 28 ›› Issue (4): 474-484.DOI: 10.17520/biods.2019290

• Original Papers: Animal Diversity • Previous Articles     Next Articles

Genetic relationships of hatchery populations and wild populations of Tanichthys albonubes near Guangzhou

Chao Li1,Jinjin Jin1,Jinzhen Luo1,2,Chunhui Wang1,3,Junjie Wang1,Jun Zhao1,*()   

  1. 1 Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong Provincial Engineering Technology Research Center for Environmentally-friendly Aquaculture, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou 510631
    2 Foshan Nanhai Shimen Senior High School, Foshan, Guangdong 528225
    3 Guangzhou Kingmed Center for Clinical Laboratory, Guangzhou 510330
  • Received:2019-09-17 Accepted:2019-12-24 Online:2020-04-20 Published:2020-06-15
  • Contact: Jun Zhao

Abstract:

Tanichthys albonubes is a popular ornamental fish species which had been believed to be extinct in the wild in China. Since 2003, many wild populations have been found on Hainan and Guangxi provinces and therefore the conversation status has been modified to be Critically Endangered. We investigated the genetic relationships of hatchery populations of T. albonubes to their wild populations near Guangzhou. To study these genetic relationships, multilocus data (one mitochondrial gene, two nuclear genes and 13 microsatellite loci) from 186 individuals from three hatchery populations and four wild populations around the city of Guangzhou were analyzed. The K2P genetic distances based on the Cyt b gene among wild populations and hatchery populations of T. albonubes ranged from 0.005 to 0.015, and from 0.001 to 0.009, respectively. Phylogenetic relationships showed hatchery population Fangcun contained four mitochondrial clades, two of which grouped with haplotypes from two wild populations near Guangzhou while the remaining clustered separately. The haplotype networks revealed that the Qingyuan population consisted of one shared haplotype with population Fangcun, which had greater haplotype diversity than all other populations. STRUCTURE analyses from the hatchery and wild populations suggested these populations could be grouped into two clusters (K = 2), one of which was formed by a hatchery population and a Qingyuan population while the other was formed by two wild populations. Principal component analysis showed that hatchery populations and Qingyuan populations overlapped with some degree of genetic variation with these cultured stocks. Directional gene flow was detected from population Qingyuan to population Fangcun using IMa3 programme. Based on these findings, we conclude that population Fangcun originated from multiple wild populations near Guangzhou and subsequently served as the ancestor of cultured populations in Singapore and Canada. We propose that irregular releases of cultured stocks of T. albonubes should be forbidden and captive hatchery using different wild populations should be prevented. At the same time, genetic resources management and sustained monitoring of hatchery and wild populations of T. albonubes should be reinforced in the future.

Key words: Tanichthys albonubes, mitochondrial DNA, nuclear gene, microsatellite, gene flow