Adão Jose Cardoso

Polymorphism of the nucleolus organizer regions (NORs) in Physalaemus petersi (Amphibia, Anura, Leptodactylidae) detected by silver staining and fluorescence in situ hybridization.

The nucleolus organizer regions (NORs) of both karyotypes I and II of Physalaemus petersi (Jiménez de la Espada, 1872) from the Brazilian Amazon were studied by Giemsa staining, and by the Ag- NOR method. Karyological group I specimens were also studied by the fluorescence in situ hybridization (FISH) technique. Multiple NOR-bearing chromosomes were detected in both karyotypes. The coincident results of the Ag-NOR and FISH methods rule out the occurrence of silent NORs in this anuran. There was no intraindividual NOR variability in either group, but interindividual variability of NORs was high in group I. Seven different patterns of active NOR distribution were definitely recognized among fifteen specimens. This was considered to be a NOR site polymorphism. These results, combined with the C-band polymorphism previously reported for P. petersi, demonstrate a high rate of chromosome evolution in this group.

Advertisement Call Variation in the Leptodactylus Mystaceus Species Complex (Amphibia: Leptodactylidae) with a Description of a New Sibling Species

Whereas morphological analysis of populations recognized as Leptodactylus mystaceus indicates there is one species with modest geographic variation, analysis of advertisement calls indicates there are at least two or perhaps three species involved. The differences found in advertisement calls are sufficient to act as species isolating barriers to recognize at least two species, which action is taken. A consequent result is the description of a new sibling species. The significance of sibling species in the genus Leptodacytylus is discussed briefly.

Cytogenetic analysis of three Physalaemus species (Amphibia, Anura)

Abstract Physalaemus biligonigerus, P. fuscomaculatus and P. sp. have 2n=2 chromosomes, consistent with the number of chromosomal pairs found in the genus.There were no substantial differences in the karyotypes of the three species, except for chromosome 3 which was submetacentric in P. fuscomaculatus and metacentric in P. biligonigerus and P. sp.All chromosomes were characterised by the presence of a C-band in the pericentromeric region. Some interstitial bands were also detected at the same position in all karyotypes, but the band located on the short arm of chromosome 3 was larger in P.biligonigerus and P. sp. than in P. fuscomaculatus.Also, only P. sp. had a large block of pericentromeric heterochro-matin in the short arm of chromosome 9 and another one in the telomeric band on the long arm. The NOR was located on the long arm of chromosome 9 in the three species. These findings confirmed that the three species are indeed closely related cytogenetically.

A second case of multivalent meiotic configurations in diploid species of Anura

We analyzed the meiotic chromosomes of specimens from the two karyological groups of Physalaemus petersi (Jimenez de la Espada, 1872) described in the literature. Multivalent configurations (rings or chains) were observed in both groups. This meiotic organization resulted from the terminal association of non-homologous chromosomes, and an analysis of C-banded multivalents indicated no involvement of heterochromatic regions in these associations. A possible explanation for such meiotic configurations is the occurrence of heterozygous translocations. Thus, multivalents may indicate the involvement of translocation events in the karyotypic evolution of P. petersi.

Reconhecimento do grupo rizibilis; descrição de uma nova espécie de Hyla (Amphibia, Anura)

Hyla ranki, sp. n., is described from the state of Minas Gerais, southeastern Brazil. This new species resembles Hyla rizibilis Bokermann, 1964. The advertising call and the tadpole are also described. Observations on the biology of the new species are referred and the recognition of the group rizibilis, constituted by H. rizibilis and H. ranki, sp. n., is proposed. Hyla mirim B. Lutz, 1972 is synonymized with H. rizibilis.

Caracterização bio-acústica da população topotípica de Hyla rubicundula (Amphibia, Anura)

The physical parameters of vocalizations in Hyla rubicundula are analyzed in the topotypical population and some requirements for this kind of analysis are discussed.