The complete mitochondrial genome of Mesogobio lachneri (Cypriniformes: Gobionidae) from Northeast Asia

Pleistocene Landscape Dynamics Drives Lineage Divergence of a Temperate Freshwater Fish Gobio rivuloides in Coastal Drainages of Northern China

Understanding historical processes underlying lineage distribution patterns is a primary goal of phylogeography. We selected Gobio rivuloides (Cypriniformes: Gobionidae) as a model to improve our knowledge about how intraspecific genetic divergence of freshwater fishes arises in coastal drainages of northern China via statistical analysis using cytochrome b gene. The time-calibrated phylogeny of G. rivuloides showed the divergence of two major lineages (I and II) at ~0.98 Ma (million years ago). Lineage I can be divided into two sub-lineages (I-A and I-B) with a divergence time of ~0.83 Ma. Sub-lineage I-A inhabits the Amur River, and sub-lineage I-B lives in the Luan River and Liao River. Lineage II is distributed in the Yellow River and Hai River, with close genetic relationships between the two drainages, and can be split into two sub-lineages (II-C and II-D) with a divergence time of ~0.60 Ma. Our findings indicate that the splitting of lineages and sub-lineages could be attributed to geographic isolation caused by the formation of the Bohai Sea, river capture, and the episodic hydrologic closing of a paleolake during the late Lower-Middle Pleistocene. It is also the first report we know of displaying a clear phylogeographic break for freshwater fishes across coastal drainages in northern China.

Complete mitochondrial genome of Belligobio pengxianensis (Cypriniformes: Gobionidae)

Belligobio pengxianensis is a small fish endemic to the upper Yangtze River of China. In this study, the complete mitochondrial genome of B. pengxianensis is determined for the first time, and it should become a reference sequence to aid in species identification, biodiversity monitoring and conservation. The mitogenome has overall length of 16,610 bp and AT content of 55.23%, including 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs, and one non-coding control region. The results of phylogenetic analyses show that B. pengxianensis is nested within the genus Hemibarbus.