Relative yield of two transferrin phenotypes in coho salmon

Experimental groups of coho salmon (Oncorhynchus kisutch) of transferring types AA and AC were compared to determine relative growth and survival before release, yields from the fishery, and returns of fish to the hatchery as 2- and 3-yr-olds. In the hatchery, growth was faster and survival higher in the AA than in the AC types. However, yields of AA and AC types were equal, although the yield of AC types as 3-yr-olds was greater than that of AA types because more of the AA males matured in 2 years. We concluded that it would be futile to attempt to increase the yield of coho salmon by maximizing the frequency of biochemical phenotypes that display only a temporary advantage over other types.