Karyotypic Characteristics of Pelophylax ridibundus

Karasu Basin in Erzurum provincial boundary is the source of the Euphrates River. Marsh frog is one of the amphibian species that is inhabited in Karasu Basin. The karyotypic characteristics of Pelophylax ridibundus have been investigated by examining metaphase chromosomes spreads obtained from bone marrow and intestine epithelium. The frogs used in the study were caught from three stations of the Karasu Basin. The cells from bone marrow and intestine of the frogs were used for karyotype analysis. The best treatment parameters for preparing good metaphase chromosome spreads from the cells were optimized as hypotonic 1 hour (0.075 M KCl) treatment and fixation with cold carnoy. The slides were stained 10% Giemsa for 20 minutes. It was determined that P. ridibundus had 2n=26 chromosomes by investigation of the chromosome spreads. The karyotype of P. ridibundus was determined as composed of 6 metacentric, 6 submetacentric and 1 subtelocentric chromosome pairs (12M+12SM+2ST). The fundamental arm number (FN) was 52 and index of karyotype symmetry/asymmetry was 1.61