ShuiEro ... from vague up to sometimes ;) crystal clear drop by drop ...

For their restricted distribution and strongly associate to evolutionary history and geological events,the freshwater fishe were usually used in biogeography studies. Macropodus opercularis(Perciformes,Belontiidae),a popular small freshwater ornamental fish,was originated in China from Yangtze basin to South China region including Hainan Island and Taiwan Island,and also could be founded in North Viet Nam.M.opercularis is an air breather,the male will build bubble nest and collect the fertilized eggs to the nest in breeding season,and is a special species on phylogeographic study.The population of M.opercularis had reduced rapidly in recent years due to environment depravation and improper exploitation.In this study,the population genetic variations and phylogeographical pattern of 123 M.opercularis from 23 sample sites including Pearl River,Jianjiang River, Moyangjiang River,Ganjiang River,Hanjiang River,Huangganghe River,Jiulongjiang River and Minjiang River,totally 8 river basins were investigated based on 400 bp nucleotide sequences of mtDNA partial control region and 3' end sequences nearby.The sequence analysis results showed that only 13 variable sites on the sequences(3.25%), include 3 haplotype pattern variable sites and 10 parsimony informative sites, no site with alignment gaps or missing data was found.The samples fall into 11 haplotypes, with only 0.576 haplotype diversity and 0.00818 nucleotide diversity.The Pearl River basin populations had unique haplotypes,populations from Guangzhou-tianhe,Panyu,Wuzhou and Daxin had one haplotype respectively,and populations from Luocheng,Huizhou had two haplotypes respectively.Haplotype H1 and H2 distributed most widely,H1 distributed on 23 samples(19%) from the Pearl River,Jianjiang River,Moyangjiang River and Hanjiang River, and H2 distributed on 75 samples(62%) of all drainage systems except for Jianjiang River. Haplotype H3 was shared by populations of Jianjiang River,Moyangjiang River and Ganjiang River. The haplotypes minimum spanning network for M.opercularis didn't showed clades corresponding to sample sites and showed star-like radiation.H1 and H2 were in the highest flight,and they were connected with 6 mutations via H3.Unique haplotypes of Xijiang River middle and upper reaches surrounded H1,unique haplotypes of Dongjiang River and Pearl River delta surrounded H2. Analysis of molecular variance(AMOVA) revealed that most of the genetic variation resides among populations within a geographic region(54.08%),which indicate that isolation among drainage systems is the key factor producing genetic diversity among populations of M.opercularis. Mismatch distribution and neutrality tests indicated that M.opercularis in this research hadn't experienced population expansion.Individuals of different river basins distributed motleyly,suggest that all populations revealing lineage sorting and high gene low between populations.The network revealed that M.opercularis might had 2 origins in Pearl River basin, one was Xijiang River middle and pper reaches,the other was Dongjiang River and Pearl River delta. Some fish samples from different river basins share the same haplotypes,indicating that some of the drainage systems had physical connection before they became geographically separated. Although M.opercularis could expand widely in a short period of time,the population had suffered serious bottleneck effect recently,and should be paid more attention to protect.