Improvement of Quality in the Common Carp by Crossbreeding

Abstract

In order to obtain hybrids that combined the economic advantages of two parent races of the common carp, Cyprinus carpio, we produced not only F1 hybrids of Japanese, Chinese, and various European races, but also progeny of various intercrosses of the F1 generations, backcrosses, and modified triple or multiple crosses. Definite heterosis was found in seven of twelve F1 hybrids. Of the F1 hybrids, the products of a cross between female yamato and male mirror carps (YM) had the highest growth rate. The growth rate and efficiency of feed conversion of the YM exceeded those of both the maternal and the paternal race; the latter (the mirror) had the fastest growth rate and the highest feed-conversion efficiency of any of the parent races used. The YM, due to their high resistance to Gyrodactylus or fungus infections, also had a higher survival rate than did either parent race. All YM are scaly, which is a preferred character in Japan. Most progeny from F1 intercrosses, backcrosses, and triple crosses, however, were economically less desirable than the YM; only the progeny from a multiple cross, (yamato ♀ × scaly German ♂) ♀ × (wild ♀ × mirror ♂) ♂, grew faster and converted feed more efficiently than the YM. The difference between the survival rates of these progeny, the YM F1 generation, and the yamato carp was negligible. We conclude that the hybrid progeny from the multiple cross are the most economically valuable carp of those studied. © 1980, The Japanese Society of Fisheries Science. All rights reserved.