Population Structure of Nga Myin Yinn Silonia Silondia in the Ayeyarwady River, Myanmar, by Mitochondrial DNA Markers

The Silond catfish Silonia silondia, locally known as Nga Myin Yinn, is a commercially important fish in Myanmar; however, fundamental knowledge of its population structure is insufficient. Specimens caught in different regions of the Ayeyarwady River, the basin of which is the country’s largest, from 2017 to 2019 were used to sequence two mitochondrial (mt)DNA genes, cytochrome b and ATPase 6/8, for investigating population differentiation. Phylogenetic trees and pairwise fixation index values revealed that the populations of S. silondia differed between Myanmar and Bangladesh/India, whereas the populations and mtDNA haplotypes were not significantly different among four regions of the Ayeyarwady River (Ayeyarwady, Yangon, Magway, and Mandalay). In addition, no unique haplotype was observed, given the lack of nucleotide diversity. Thus, S. silondia in the Ayeyarwady River can be considered a single population, which is different from those of Bangladesh/India. Our study provides the first content for understanding the genetic diversity of S. silondia in the Ayeyarwady River in Myanmar according to molecular analyses. These genetic data will be useful for understanding the genetic diversity of this species in South and Southeast Asia.