We conducted MIG-seq to analyze the population structure of deep-sea fishes. Three species (Chimaera phantasma, Pyramodon ventralis, and Neoscopelus microchir) are included in this project. DNA barcoding of mt DNA suggested that these three species may be cryptic species.Therefore, this project was conducted to examine whether there are interspecific differences by genome-wide SNPs.The MIGseq results, as well as the DNA barcoding, indicate that there is significant genetic variation within species.