Chromosomal Studies in Twelve Species of Leptodactylidae and one Brachycephalidae

Abstract

SUMMARYKaryotypes of twelve species of Leptodactylidae and one Brachycephalidae were studied. They were: Eleutherodactylus unistrigatus (2n=20), Holoaden bradei (2n=18), Paralelmatobius lutzi (2n=24), Physalaemus aguirrei, P. cicada, P. gracilis, P. kroyeri, P. sp. (1), P. sp. (2), P. olfersi, P. signiferus, P. soaresi (2n=22) and Melanophryttiscus moreirae (2n=22). Centric fusion and pericentric inversions are the most important mechanisms of karyotype differentiation in Leptodactylidae. Melanophryniscus moreirae, of the Brachycephalidae family, presents a karyotype related to those of the Bufonidae. No morphologically distinguishable sex chromosomes could be observed.