Distant hybridization can combine together the genomes of different species, which leads to changes of the offspring in phenotypes and genotypes. In this study, we successfully establish a fertile hybrid lineage by intergeneric hybridization of female blunt snout bream (BSB, Megalobrama amblycephala)×male topmouth culter (TC, Culter alburnus) and investigate some important biological traits of this lineage including the morphological traits, chromosomal number, karyotype, DNA content, gonadal development, egg and milt yield, sperm shape and density, fertilization rate and early survival rate. The results show that: (1) the diploid and triploid hybrids coexist in F 1 and only diploid hybrids are found in F 2 , in which the diploid hybrids of F 1 and F 2 possess 48 chromosomes with one chromosome set of BSB and one chromosome set of TC, and the triploid hybrids of F 1 possess 72 chromosomes with two chromosome sets of BSB and one chromosome set of TC. (2) All the tested males and females of the diploid F 1 and F 2 hybrids have the normal gonadal development and produce mature sperm and egg, respectively, which are fertilized with each other to form F 2 and F 3 hybrids, respectively, and finally form a diploid hybrid lineage (F 1 –F 3 ). (3) The good fertility of the F 1 and F 2 hybrids of female BSB×male TC potentially provides reproductive base to make the hybrid lineage propagate from one generation to another. The formation of the hybrid lineage (F 1 –F 3 ) also provides an ideal model to research the reproductive rules of distant hybrid progeny.