Natural hybrids of Branchiostegus japonicus and B. auratus landed at Nagasaki and Oita fish market

Two possible hybrid specimens, one from Oita fish market and the other from Nagasaki fish market, were obtained. The specimens had the characteristics of both red tilefish Branchiostegus japonicus (a silvery white triangular marking from the posterior orbital to the mid preoperculum) and yellow tilefish Branchiostegus auratus (a silvery white band from the suborbital to the upper jaw, small yellow spots on the surface of the caudal fin). In the present study, the possible hybrid specimens were evaluated in comparison with B. japonicus and B. auratus. Numerical characters of the specimens were within the range of overlapping of B. japonicus and B. auratus. By employing discriminant analysis and principal component analysis based on the morphometric indices, the results revealed that the specimens showed intermediate characteristics of morphometrics between the two species. It is confirmed that the two samples carry the genes associated with both B. japonicus and B. auratus based on nuclear DNA analyses. In conclusion, the two specimens were considered as natural hybrids among B. japonicus and B. auratus.