The Formation and Biological Characteristics of the Hybrids Derived from the Hybridization of Japanese White Crucian Carp × Red Crucian Carp

Abstract

As described in the previous chapters, many fish lineages or populations were obtained by hybridization, backcrossing, gynogenesis (androgenesis), self-crossing. These fertile lineages or populations are very useful in genetics, breeding, and biological evolution. In this chapter, we introduce a new hybrid lineage derived from the hybridization of Japanese white crucian carp (Carassius cuvieri, ♀, 2n = 100, WCC) × red crucian carp (Carassius auratus red var., ♂, 2n = 100, RCC), and the improved fish (WR-II) obtained by backcrossing of the hybrids and the WCC. Both WCC and RCC are important economic fish. WCC is characterized by fast growth, silver body color, poor meat quality, and weak stress resistance. RCC is characterized by perfect meat quality, strong stress resistance, and red body color. Hybridization can combine genomes of parent species, which may lead to changes in phenotype and genotype of the hybrids. And hybridization is accompanied by the emergence of advantageous traits. Therefore, we choose WCC and RCC as parents to produce a new kind of fish with strong stress resistance, fast growth, and good meat quality. After a lot of experimental research, we choose the hybrid combination in which the WCC is used as the maternal parent and RCC is used as the paternal parent to produce high-quality hybrid fish. Through successive breeding, we establish a new hybrid lineage and a new kind of improved fish (WR-II). In this chapter, we make a detailed introduction of the biological traits and genetic characteristics of distant hybridization of female WCC × male RCC and the new type of improved fish (WR-II).