The Basic Biological Features of Allotetraploid Lineage of Red Crucian Carp × Common Carp

The allotetraploid lineage of red crucian carp (Carassius auratus red var., ♀) × common carp (Cyprinus carpio L., ♂) has been propagated to generation 27 (F3–F29) and formed a fertile allotetraploid lineage. The formation of the allotetraploid lineage provides new germplasm resource for aquaculture and suitable model for studying polyploidization. This established allotetraploid lineage provides a new approach for fish breeding. By distant hybridization, this novel allotetraploid fish with two subgenomes shows changes in phenotypes and genotypes. The comprehensive investigation of the features of this allotetraploid lineage provides evidences for the role of distant hybridization in polyploidization events. This chapter mainly introduces the appearance, chromosome ploidy, gonadal development and breeding, diploid gametes, growth performance, and other biological features of the allotetraploid hybrids.