In this study, the Turkish population of Rattus norvegicus and Rattus rattus were studied with regard to external, cranial, phalli, bacula and tooth crown morphology and karyotype. External, internal and karyologic characteristics of R. norvegicus were found to be consistent with previously published results. Additionally, it was determined that there are striking color variations in the dorsal and ventral fur of R. rattus and that crown morphology is not a definitive characteristic distinguishing these species because of connected lobes in old specimens. According to the karyological studies, the diploid chromosome numbers and fundamental numbers of R. norvegicus and R. rattus were found to be 42, 38 and 64, 60, respectively.
YİĞİT, Nuri; ÇOLAK, Ercüment; SÖZEN, Mustafa; and ÖZKURT, Şakir (1998) "The Taxonomy and Karyology of Rattus norvegicus (Berkenhout, 1769) andRattus rattus (Linnaeus, 1758) (Rodentia: Muridae) in Turkey," Turkish Journal of Zoology: Vol. 22: No. 3, Article 6. Available at: https://journals.tubitak.gov.tr/zoology/vol22/iss3/6