C-banding patterns inSalmo trutta,a species of tetraploid origin

Salmo trutta is a species of tetraploid origin in the process towards diploidization. By their C-banding pattern, some chromosomes demonstrated homology in the disomic stage, whereas others are tetrasomic. An attempt is made to arrange a karyotype according to this presumptive homology. AsS. irideus (Ohno et al., 1965), andS. salar (Roberts, 1968),S. trutta showed inter- and intra-individual Robertsonian variation. 53 analysed metaphases showed chromosome counts ranging from 77 to 82. The chromosome arm count (FN) was found to be consistently 102.