The formation of hybrid fish derived from hybridization of Megalobrama amblycephala (♀) × Siniperca chuatsi (♂)

Abstract Crossbreeding has been conducted in many fish species. However, crosses between distant relatives that may result in higher levels of heterosis are hard to conduct due to reproductive isolation. In this study, diploid hybrids (BM) of blunt snout bream (Megalobrama amblycephala, BSB, ♀, order Cypriniformes, 2n = 48) × mandarin fish (order Siniperca chuatsi, MD, ♂, Perciformes, 2n = 48) were successfully produced. BM possessed 48 chromosomes from BSB. The body colour of BM (silver grey with many black spots) was different from that of BSB (silvery white) and MD (yellow with black stripes). The body shape of BM (small head with a slender body) was different from that of BSB (small head with a high back) and MD (body larger and flatter). We confirmed successful hybridization with microsatellite DNA markers and analysed the 5S rDNA patterns among the parental and hybrid lines. BM inherited its 5S rDNA entirely from the female parent (BSB). This study will provide a foundation for fish crossbreeding, and the successful hybrids in this study will potentially be an excellent commercial variety.