Update data files. upload new datafiles Update publication information. Heterosis is a complex biological phenomenon in which hybridization exhibit superior phenotypic characteristics. The underlying molecular basis for heterosis, particularly for fishes, remains elusive. In this study, we used next-generation sequencing technologies and tandem mass tags to characterise mRNA-seq, miRNA-seq and proteomic of Pelteobagrus fulvidraco, P. vachelli and hybrid yellow catfish Huangyou-1 (P. fulvidraco ♀×P. vachelli ♂) livers and in doing so, offer deeper insight into the transcriptional and protein changes in heterosis uncovers key roles for miRNAs.