Co-Authors:
Wohlfarth, G.W., Agricultural Research Organization, Fish and Aquaculture Research Station, Dor, Israel
Abstract:
The growth of crossbreds of common carp and their parental strains was compared. Heterosis, defined as growth of the crossbred exceeding that of its faster growing parent, was demonstrated in cases involving isolates from different farms or countries. As a rule, heterosis was not found when one of the parental lines was Dor-70, a line generated in a long-term mass selection experiment for faster growth. Heterosis was found commonly in young-of-the-year carp during their first summer. In winter and adult tests, significant differences between crossbreds and their better parent were rare. The crossbred between the Chinese and European races of common carp was heterotic only in an environment permitting an intermediate growth rate. We conclude that heterosis for growth is a common but not universal phenomenon in carp. It is limited by genetic factors, genotype-environment interactions, and age and weight of fish. The application of heterosis to aquaculture is discussed. © 1993.