Principles of Genetics and Breeding

5.1.8.2 Growth potential of hybrids

The growth of hybrids mostly appears to be intermediate between that of the parental species. The fast growing species transmit at least partly this potential to the hybrids in salmonids. The development of “hybrid vigour” (heterosis) therefore seems to be limited to crosses between different groups of the same species and not to hybridization between two different species. Although intermediate for growth and survival, the hybrid can sometimes be of economic value when it appears as a compromise between a fragile, fast growing species and a more hardy, but slow growing one. The hybrid may be of interest too when only one of the parental species is domesticated and liable to supply eggs easily, the sperm being collected in a wild, fast growing species.