Taxonomic implications from phylogenetic relationships of subspecies ofSchizopygopsis malacanthus(Pisces: Cyprinidae) based on sequence analysis of cytochromeband mitochondrial DNA control region

Abstract

Phylogenetic relationships of three subspecies of Schizopygopsis malacanthus, S. m. malacanthus, S. m. chengi, and S. m. baoxingensis, were investigated based on the mitochondrial DNA control region and the cytochrome b gene. Phylogenetic analysis indicated that the three subspecies did not cluster as one monophyletic group; S. m. malacanthus clustered into one clade, while S. m. chengi and S. m. baoxingensis clustered into another. Genetic distances between S. m. malacanthus and the other two subspecies were either very close to or larger than those between S. m. malacanthus and some other species of Schizopygopsis. There was very small genetic distance between S. m. chengi and S. m. baoxingensis. The results suggested S. m. chengi should be split from S. malacanthus into a separate species, Schizopygopsis chengi (Fang); S. m. baoxingensis should be regarded as a subspecies, S. c. baoxingensis (Fu, Ding et Ye), of Schizopygopsis chengi.

Limited genetic diversity of an endemic subspecies Schizopygopsis chengi baoxingensis as inferred from the mitochondrial DNA control region

“…It was classified as a subspecies of Schizopygopsis malacanthus Herzenstein, S. m. chengi (Tsao & Tun, 1962). Yu et al (2006) suggested S. m. chengi as a separate species, S. chengi, and another subspecies of S. malacanthus, S. m. baoxingensis, as a subspecies of S. chengi, according to phylogenetic analyses of the mitochondrial DNA control region and the cytochrome b gene. Schizopygopsis c. baoxingensis might have evolved from S. chengi as a result of geological events in the Jiajin Mountain area (Yu et al, 2006).…”

“…Yu et al (2006) suggested S. m. chengi as a separate species, S. chengi, and another subspecies of S. malacanthus, S. m. baoxingensis, as a subspecies of S. chengi, according to phylogenetic analyses of the mitochondrial DNA control region and the cytochrome b gene. Schizopygopsis c. baoxingensis might have evolved from S. chengi as a result of geological events in the Jiajin Mountain area (Yu et al, 2006). Schizopygopsis c. baoxingensis is endemic to the East River (Baoxing) of the upper reaches of the Qingyi River, a tributary of the Minjiang River in China, and exists as one unique population along a 60-km long stretch of stream above the Yanjing region of the river (Song, 2006) (Fig.…”

“…Schizopygopsis c. baoxingensis is separated from S. chengi by Jiajin Mountain, and Yu et al (2006) suggested that it originated from S. chengi as a result of stream capture or some other geological events in the area. Perhaps, as a result of these factors, some S. chengi individuals became separated from the Dadu River water system and evolved into the existing S. c. baoxingensis.…”

“…1). This subspecies should have special value in fisheries conservation in China, and might have potential value in studies of geological movement in the Jiajin Mountain area (Yu et al, 2006). Meanwhile, the subfamily Schizothoracinae (Pisces, Cypriniformes, Cyprinidae) are significant for studying the uplift of the Tibetan Plateau.…”

“…The remaining two were downloaded from GenBank (accession nos. DQ533785 and DQ533786), and were previously deposited by our laboratory (Yu et al, 2006) (Table 1). All nucleotide sequences were initially aligned using the Clustal X 1.8 multiplealignment program (Thompson et al, 1997) with the default settings, and then refined manually.…”