New insights on geographical/ecological populations within Coilia nasus (Clupeiformes: Engraulidae) based on mitochondrial DNA and microsatellites.

The Coilia nasus is an important fish species, which is of commercial values in China. In order to manage the fisheries resources and the development of sustainable fishing strategies to protect this species, 11 microsatellite loci polymorphisms and mtDNA COI sequences were used to examine the genetic diversity of C. nasus in Japan and China. In total, the 40 COI haplotypes and 93 microsatellite alleles were detected. The mtDNA phylogeny did not support population grouping, but the distribution patterns of mtDNA haplotypes and the results of STRUCTURE analysis based on microsatellite indicated a degree of genetic isolation in this species. Our study suggested that the lack of a population genetic structure might result in its amphidromous life cycle, and the geographical distance and habitat fragments might cause isolated populations. Thus, the sampling populations of C. nasus in Japan and China could be divided as four geographical/ecological populations.

The population history of Garra orientalis (Teleostei: Cyprinidae) using mitochondrial DNA and microsatellite data with approximate Bayesian computation.

BACKGROUND: The South China landmass has been characterized by a complex geological history, including mountain lifting, climate changes, and river capture/reversal events. To determine how this complexity has influenced the landmass's phylogeography, our study examined the phylogeography of Garra orientalis, a cyprinid widely distributed in South China, using sequences from the mitochondrial DNA control region and cytochrome b gene (1887 bp) and polymorphisms of thirteen microsatellite loci. RESULTS: In total, 157 specimens were collected from eight populations. All 88 mtDNA haplotypes were identified as belonging to three major lineages, and these lineages were almost allopatric in their distributions. The results of a statistical dispersal-vicariance analysis suggested that the ancestral populations of G. orientalis were distributed south of the Yunkai Mountains, including on Hainan Island. The mtDNA data revealed a strong relationship between phylogeny and geography. In the microsatellite analysis, a total of 339 alleles with an average of 26 alleles per locus were observed across thirteen microsatellite loci. A clustering algorithm for microsatellite data revealed an admixture-like genetic structure. Although the mtDNA and microsatellite data sets displayed a discordant population structure, the results of an approximate Bayesian computation approach showed that these two markers revealed congruent historical signals. The population history of G. orientalis reflects vicariance events and dispersal related to the complex geological history of South China. CONCLUSION: Our results (i) found that the discordances between mtDNA and microsatellite markers were accounted for by admixtures; (ii) showed that the Wuzhishan and Yinggeling mountain ranges and Qiongzhou Strait were important barriers limiting gene exchange between populations on both sides; (iii) indicated that during glaciation and inter-glacial periods, the strait and continental shelves were exposed and sank, which contributed with the dispersion and differentiation of populations; and (iv) displayed that the admixtures between lineages took place in coastal populations and then colonized the tributaries of the Pearl River.

Complete mitochondrial DNA sequence of globe fish Tetraodon lineatus (Linnaeus, 1758) and the phylogenetic analysis of tetraodontidae.

Globe fish, Tetraodon lineatus (Linnaeus, 1758) is an ornamental freshwater fish in China. In this study, the complete mitochondrial genome of globe fish was first determined. The entire mitochondrial DNA sequence (mtDNA) sequence was 164595bp in length and consisted of 13 protein-coding genes, 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs) and a control region (CR). Its mitochondrial genome had the common features with those of other bony fishes with respect to gene arrangement, base composition, and tRNA structures.

The complete mitogenome of the oriental sucking barb, Garra orientalis (Cypriniformes, Cyprinidae): repetitive sequences in the control region.

The oriental sucking barb, Garra orientalis, is a small to moderate-sized freshwater fish. In this study, the complete mitochondrial genome of G. oriental was successfully sequenced for the first time with total length of 17,288 bp. The genome structure consists of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA (tRNA) genes and a control region. Moreover, tandem repeat unit ranged from 259 to 260 bp (repeated 3-4 times) was identified in the control region among G. orientalis individuals.