The mitotic chromosomes of the newt species Triturus marmoratus and T. cristatus were submitted to the C -staining method. All the centromeres are darkly stained and single darkly stained bands are induced on both sides of the centromere regions as well as on various chromosomes in subterminal position. Therefore, the C-bands allow the identification of the single elements of the complements and their more exact arrangement into karyotypes. In both species, the sex chromosomes show an extensive dark segment along the long arm corresponding to the heteromorphie region of lampbrush chromosomes I. In spite of the different number and location of the nucleolus-organizing regions and some discrepancies concerning certain subterminal bands, the two karyotypes appear of similar morphology and structure. There is no evidence for extensive structural rearrangements: probably T. marmoratus and T. cristatus have mostly undergone a certain differentiation caused by allelic changes in single genetic loci during the processes of karyological evolution and speciation.
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Con il contributo del Ministero per i Beni e le Attività Culturali