A Comparative Study of the Chromosomes in the Chum Salmon, the Kokanee Salmon and their Hybrids

Abstract
The somatic chromosomes were studied in the chum salmon (Oncorhynchus keta), the kokanee salmon (O. nerka) and their hybrids, by application of the routine air-drying method. The diploid numbers were 74 for the chum salmon and 58 for the kokanee salmon. Their hybrids showed 66 chromosomes corresponding to a total sum of the haploid number of the parent species. The chromosome formula based on the total numbers of chromosome arms were 100+6m = 106 for the chum salmon, 102+2m = 104 for the kokanee salmon and 101+4m=105 for the hybrids.