Amplified fragment length polymorphism (AFLP) technique was used to assess genetic variation and population structuring of Coreoleuciscus splendidus (Teleostei; Cypriniformes) from four major river drainage systems in South Korea (i.e. the Han and Geum Rivers belonging to the West Korea Subdistrict and the Seomjin and Nakdong Rivers belonging to the South Korea Subdistrict). Four combinations of selective primers generated 152-186 DNA fragments, of which 45-59 were polymorphic. The Geum River population had the lowest genetic variation in terms of average heterozygosity. The pairwise genetic differentiation (FST) estimates showed that the four populations of C. splendidus were genetically differentiated (P < 0.05).The FST values were higher between population groups of the West and South Subdistricts than between populations from the two river systems within each subdistrict. A dendrogram based on the distance matrix revealed that all C. splendidus individuals bifurcated into two subdistrict population groups and were further divided into two river populations within each subdistrict. Individuals from each population consistently clustered together with high statistical support. The analysis of molecular variance after partitioning of C. splendidus populations into two groups (i.e. the West and South Korea Subdistricts) revealed very strong geographic structuring between them with 74.01% of total variance (P < 0.001). Taken together, the AFLP markers clearly distinguished not only between two population groups of the West and South Subdistricts but also between populations from two river systems within each subdistrict. Morphological differences between the two subdistrict population groups in body color and the presence of black array(s) on dorsal, anal, and caudal fin rays agreed with their high degree of genetic variation. Our findings strongly indicate that restricted dispersal and gene flow are apparent among four geographically separate populations of C. splendidus, and each population should be treated as an evolutionarily significant unit; this should be an a priori consideration for developing their conservation strategies.

Coreoleuciscus splendidus was first reported as a monotypic species. Recent morphological and genetic studies have revealed that the species is represented by two disjunct and distinct lineages. The two lineages of C. splendidus include populations inhabiting the Han and Geum rivers in the East Korea Subdistrict and populations inhabiting the Seomjin and Nakdong rivers in the South Korea Subdistrict. In this study, significant differences were found between these two independent lineages through a high degree of genetic divergence in the mitochondrial cytochrome c oxidase subunit I gene as well as conspicuous morphological differences in body coloration and shapes of black stripes on dorsal, anal and caudal fin rays. These morphological and genetic differences provide supporting evidence that the populations in the South Korea Subdistrict represent a new species, Coreoleuciscus aeruginos.

The complete mitochondrial genome of a bagrid catfish, Tachysurus nitidus was completely analyzed by the primer walking method. It was composed of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region with a total length of 16,537 bp. In the phylogenetic tree, using mitochondrial genome of 13 related sequences revealed that T. nitidus (MW451217) of Korea is clustered with T. nitidus (KC822643) of China. This complete mitochondrial genome provides an important resource for reviewing the phylogenetic relationships and taxonomic status of the bagrid species.

No abstract

No abstract