Fertilization and growth performance in reciprocal hybrids of Dianchi golden-line barbel (Sinocyclocheilus grahami) and domestic common carp (Cyprinus carpio) and crucian carp (Carassius auratus)

Abstract

Hybridization has been successfully achieved using Dianchi golden-line barbel (Sinocyclocheilus grahami) and barbless carp (Cyprinus pellegrini) as parental species. However, little is known about the crossbreeding feasibility of S. grahami with domesticated common carp (Cyprinus carpio) and crucian carp (Carassius auratus). In this study, we constructed reciprocal hybrid lineages using parents of S. grahami (2n = 96) with C. carpio rubrofuscus (2n = 100) and C. auratus (2n = 100). We found that hybrids of S. grahami ♀ × C. carpio rubrofuscus ♂ survived, but with fertilization (41.6%) and hatching rates (68.2%) lower than the reciprocal hybrids (fertilization rate 92.7% and hatching rate 89.5%). Hybrids of S. grahami ♀ × C. auratus ♂ exhibited failed hatching and low fertilization (6.3%) compared with the reciprocal hybrids, which showed high fertilization (88.5%) and hatching rates (88.6%). Growth results show that hybrids of S. grahami ♀ × C. carpio ♂ (total length: 12.2 cm, body weight: 25.4 g), S. grahami ♂ × C. carpio ♀ (total length: 12.1 cm, body weight: 25.0 g), and S. grahami ♂ × C. auratus ♀ (total length: 10.1 cm, body weight: 16.7 g) achieved medium growth rates compared to their parents. Based on this study, the three hybrid lineages show fast growth performance compared to S. grahami and exhibit high commercial and aquacultural application potential.