Cytogenetic study in Salmo irideus and S. Trutta fario

S. irideus showed some variations of the chromosome number around the mode at 2n=60, as a result of increasing and decreasing the number of chromosomal arms (NF) probably through the meiotic non-disjunction. S. trutta fario was found to possess a well individualized chromosome complement, such as 2n=80 and NF=104. It differs from the complement of the original species, S. trutta, by the number of chromosome arms. The increase of the NF is caused by the presence of 1-2 supplementary pairs of meta- or submetacentric chromosomes, probably produced through duplication processes.