Mitochondrial Genome Diversity of <i>Schistura</i> McClelland, 1838 (Teleostei, Nemacheilidae)

Abstract

The inconsistency between traditional morphological taxonomy and molecular phylogenetic data is a major issue that puzzles the study of fish classification and evolution. Although mitochondrial genes are commonly used in phylogenetic analyses to compare fish species, the mitochondrial evolution and diversity of Schistura are still not well understood. To better understand the evolution of Schistura, we sequenced the mitochondrial genome of Schistura fasciolata and compared it with other species of Schistura. A 16,588 bp circular mitochondrial genome of S. fasciolata was obtained and it contains 13 protein-coding, 22 transfer RNA, and two ribosomal RNA genes, and a non-coding control region. The gene arrangement in the mitochondrial genomes of all Schistura species was consistent. However, we also found that S. fasciolata was not monophyletic. Although mitochondrial genes can be effectively used for Schistura species identification, they may not be suitable for inferring the evolutionary process of Schistura species. These results provide support for the use of mitochondrial genes in identifying Schistura species, and also serve as a warning against mistakenly using them to evaluate the evolution process of Schistura species.

Keywords

• loach
• mitochondrial genome
• evolution
• genetic diversity
• species identification