Chromosomal polymorphism caused by supernumerary chromosomes in Rattus rattus ssp. frugivurus (Rafinesque, 1814) (Rodentia, Muridae).
A chromosomal numeric polymorphism 2n = 38, 39, 40 and 41 in the species Rattus rattus ssp. frugivurus (Rafinesque, 1814) is reported for the first time for this subspecies. The numbers 2n = 39, 40 and 41 are new for the species. The polymorphism is due to the presence of 1, 2 or 3 B-chromosomes, which are all small metacentrics of the size and shaped vary close to the other autosomes of the normal complement, and whose character of being supernumeraries is shown in Meiosis.
D000818:Animals; D008540:Meiosis; D011110:Polymorphism, Genetic; D051381:Rats / Q000235:genetics*; D013030:Spain