Diploid and Triploid Hybrids Derived from Female Megalobrama amblycephala Yih × Male Xenocypris davidi Bleeker

DNA content, chromosomal number, morphological characters, aquaculture performance, and gonad development of Megalobrama amblycephala Yih (BSB) (♀) × Xenocypris davidi Bleeker (YT) (♂) hybrids were analyzed. Diploid hybrids with 48 chromosomes (2nBY, 2n = 48) and triploid hybrids with 72 chromosomes (3nBY, 3n = 72) were found in the hybrid progeny, accounting for 88% and 12%, respectively. The two kinds of hybrids exhibited phenotypic divergence and hybrid heterosis from BSB and YF. In addition, neither hybrid could produce mature eggs or sperm at 2 years old. Histological observation revealed that gonad development of the hybrids was not synchronous and exhibited abundant polymorphism. This study produced a new variety of fish with potential benefits to aquaculture. What' s more, it provides valuable materials for the ongoing gonad transcriptome sequencing work.