Interspecific differences between Odontophrynus cordobae and O. americanus (Anura: Leptodactylidae)

GRENAT, PABLO R.; SALAS, NANCY E.; MARTINO, ADOLFO L.

Huerta Grande, Córdoba, Argentina

Congreso; I Reunión Conjunta de Sociedades de Biología de la República Argentina, XVI Jornadas Científicas de la Sociedad de Biología de Córdoba, IX Jornadas de la Sociedad Argentina de Biología; 2007

Sociedad de Biología de Córdoba-Sociedad Argentina de Biología

The occurrence of natural polyploid bisexual species in amphibians provides evidences that the polyploidy is an important evolution mechanism in several families of anurans. O. cordobae (diploid) and O. americanus (tetraploid) individuals of nine localities of Córdoba province in central area of Argentina were analyzed. Two complexes of independent characters, ethological (bioacoustics) and cellular (erythrometry and cytogenetic) were used to evaluate the interspecific differences. Ploidy of the individuals was analyzed by counting the chromosomes, and the karyotype corresponding to each locality was performed. Secondary constrictions were observedin the pair 4 in diploid individuals and in the quartet 11 in tetraploids. The means of erythrocyte areas obtained for O. cordobae were between 167.67 and 172.23 µm2 and for O. americanus were between 222.23-226.63 µm2. The acoustic analysis showed significant differences among species with an evident segregation of the syntopic diploid/tetraploid populations. The use of a group of independent characters is useful for the study of related species populations. Until the present, natural hybrids have not been found. The differences suggest that the call components represent an important prezygotic isolation barrier.